Name the profiles to not suggest they're WASM-only

This way I can `cargo run --target ...` and Cargo will spawn a dummy
webserver instead of attempting to execute the WASM file on my x86/arm
CPU.

.cargo/config.toml

@@ -0,0 +1,4 @@
+
+[target.wasm32-unknown-unknown]
+runner = "wasm-server-runner"
+rustflags = ["--cfg", "getrandom_backend=\"wasm_js\""]

Cargo.toml

@@ -1,10 +1,33 @@
 [package]
 name = "asteroids"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2024"
 
 [dependencies]
-bevy = { version = "0.16", features = ["dynamic_linking"] }
+bevy = "0.16"
 bevy-inspector-egui = "0.32.0"
-bevy_rapier2d = { version = "0.31.0", features = ["debug-render-2d"] }
+bevy_rapier2d = "0.31.0"
 rand = "0.9.2"
+
+[features]
+dynamic_linking = ["bevy/dynamic_linking"]
+debug_ui = ["bevy_rapier2d/debug-render-2d"]
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.3.3", features = ["wasm_js"] }
+
+[profile.speedy]
+inherits = "release"
+codegen-units = 1
+lto = "fat"
+opt-level = 3
+strip = "symbols"
+panic = "abort"
+
+[profile.tiny]
+inherits = "release"
+codegen-units = 1
+lto = "fat"
+opt-level = "z"
+strip = "symbols"
+panic = "abort"

src/config.rs

@@ -5,6 +5,10 @@ use bevy::color::Color;
 
 pub const WINDOW_SIZE: bevy::prelude::Vec2 = bevy::prelude::Vec2::new(800.0, 600.0);
 
+pub const UI_BUTTON_NORMAL: Color = Color::srgb(0.15, 0.15, 0.15); // Button color when it's just hanging out
+pub const UI_BUTTON_HOVERED: Color = Color::srgb(0.25, 0.25, 0.25); // ... when it's hovered
+pub const UI_BUTTON_PRESSED: Color = Color::srgb(0.55, 0.55, 0.55); // ... when it's pressed
+
 pub(crate) const BACKGROUND_COLOR: Color = Color::srgb(0.3, 0.3, 0.3);
 pub(crate) const PLAYER_SHIP_COLOR: Color = Color::srgb(1.0, 1.0, 1.0);
 pub(crate) const SHIP_THRUSTER_COLOR_ACTIVE: Color = Color::srgb(1.0, 0.2, 0.2);

src/events.rs

@@ -3,15 +3,25 @@ use bevy::prelude::*;
 use crate::objects::AsteroidSize;
 
 /// Signals that the player's ship has been destroyed.
-/// Used when the player collides with an asteroid.
+///
+/// Produced by the [`fn collision_listener(...)`](`crate::physics::collision_listener`)
+/// system when the player collides with an asteroid. They are consumed by [`fn ship_impact_listener(...)`](`crate::objects::ship_impact_listener`).
 #[derive(Event)]
 pub(crate) struct ShipDestroy;
 
 /// Signals that a particular asteroid has been destroyed.
-/// Used to split (or vanish) an asteroid when a bullet strikes it.
+///
+/// Produced by the [`fn collision_listener(...)`](`crate::physics::collision_listener`)
+/// system when bullets contact asteroids. It is consumed by [`fn split_asteroid(...)`](`crate::objects::spawn_asteroid`)
+/// system, which re-emits [spawn events](`SpawnAsteroid`).
 #[derive(Event)]
 pub(crate) struct AsteroidDestroy(pub Entity);
 
+/// Signals that an asteroid needs to be spawned and provides the parameters
+/// for that action.
+///
+/// Produced by the [`tick_asteroid_manager(...)`](`crate::machinery::tick_asteroid_manager`)
+/// system and consumed by the [`spawn_asteroid(...)`](`crate::objects::spawn_asteroid`) system.
 #[derive(Event)]
 pub struct SpawnAsteroid {
     pub pos: Vec2,
@@ -19,11 +29,7 @@ pub struct SpawnAsteroid {
     pub size: AsteroidSize,
 }
 
-// TODO: BulletDestroy
+/// Signals that a particular bullet has been destroyed (after it strikes an Asteroid).
-// Which depends on the still-pending Bullet component creation.
-
-/// Signals that a particular bullet has been destroyed.
-/// Used to despawn the bullet after it strikes an Asteroid.
 ///
 /// TODO: Maybe use it for lifetime expiration (which is also a TODO item).
 #[derive(Event)]

src/lib.rs

@@ -1,3 +1,7 @@
+//! Asteroids, implemented as a Bevy plugin.
+//!
+//! Compile-time configurables can be found in the [`config`] module.
+
 pub mod config;
 mod events;
 mod machinery;
@@ -9,7 +13,7 @@ mod widgets;
 use crate::config::{
     ASTEROID_SMALL_COLOR, BACKGROUND_COLOR, BULLET_COLOR, BULLET_LIFETIME, BULLET_SPEED,
     PLAYER_SHIP_COLOR, SHIP_ROTATION, SHIP_THRUST, SHIP_THRUSTER_COLOR_ACTIVE,
-    SHIP_THRUSTER_COLOR_INACTIVE, WINDOW_SIZE,
+    SHIP_THRUSTER_COLOR_INACTIVE,
 };
 use crate::machinery::AsteroidSpawner;
 use crate::objects::{Bullet, Ship};
@@ -24,21 +28,20 @@ use bevy_rapier2d::{
 use machinery::Lifetime;
 use resources::{GameAssets, Lives, Score, WorldSize};
 
+/// The main game plugin.
 pub struct AsteroidPlugin;
 
 impl Plugin for AsteroidPlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins((
-            widgets::GameMenuPlugin,
+            widgets::PluginGameMenu,
-            widgets::preparation_widget_plugin,
+            widgets::PluginGameOver,
+            widgets::PluginGetReady,
             RapierPhysicsPlugin::<NoUserData>::pixels_per_meter(10.0),
             RapierDebugRenderPlugin::default(),
         ))
         .insert_resource(ClearColor(BACKGROUND_COLOR))
-        .insert_resource(WorldSize {
+        .insert_resource(WorldSize::default())
-            width: WINDOW_SIZE.x,
-            height: WINDOW_SIZE.y,
-        })
         .insert_resource(Lives(3))
         .register_type::<Lives>()
         .insert_resource(Score(0))
@@ -62,8 +65,6 @@ impl Plugin for AsteroidPlugin {
                 objects::bullet_impact_listener,
                 objects::ship_impact_listener,
                 physics::collision_listener,
-                // TODO: Remove debug printing
-                debug_collision_event_printer,
                 machinery::tick_lifetimes,
             )
                 .run_if(in_state(GameState::Playing)),
@@ -80,16 +81,11 @@ impl Plugin for AsteroidPlugin {
         .add_event::<events::AsteroidDestroy>()
         .add_event::<events::ShipDestroy>()
         .add_event::<events::BulletDestroy>();
-        app.insert_state(GameState::Playing);
+        app.insert_state(GameState::TitleScreen);
-    }
-}
-
-fn debug_collision_event_printer(mut collision_events: EventReader<CollisionEvent>) {
-    for event in collision_events.read() {
-        dbg!(event);
     }
 }
 
+/// The game's main state tracking mechanism, registered with Bevy as a [`State`](`bevy::prelude::State`).
 #[derive(Clone, Debug, Eq, Hash, PartialEq, States)]
 pub enum GameState {
     TitleScreen, // Program is started. Present title screen and await user start
@@ -102,9 +98,9 @@ fn spawn_camera(mut commands: Commands) {
     commands.spawn(Camera2d);
 }
 
-/*
+/// Player's thruster control system.
- Checks if "W" is pressed and increases velocity accordingly.
+///
-*/
+/// Checks if "W" is pressed and increases velocity accordingly.
 fn input_ship_thruster(
     keyboard_input: Res<ButtonInput<KeyCode>>,
     mut query: Query<(&mut physics::Velocity, &Transform, &mut Children), With<Ship>>,
@@ -135,10 +131,10 @@ fn input_ship_thruster(
     }
 }
 
-/*
+/// Player's rotation control system.
- Checks if "A" or "D" is pressed and updates the player's Rotation component accordingly
+///
- Does *not* rotate the graphical widget! (that's done by the `apply_rotation_to_mesh` system)
+/// Checks if "A" or "D" is pressed and updates the player's [`AngularVelocity`]
-*/
+/// component accordingly.
 fn input_ship_rotation(
     keyboard_input: Res<ButtonInput<KeyCode>>,
     mut query: Query<&mut AngularVelocity, With<Ship>>,
@@ -157,6 +153,12 @@ fn input_ship_rotation(
     }
 }
 
+/// Player's gun trigger.
+///
+/// Checks if the spacebar has just been pressed, spawning a bullet if so.
+///
+/// TODO: Hook up a timer to control weapon fire-rate. Something will have to
+/// tick those timers. Maybe this system?
 fn input_ship_shoot(
     keyboard_input: Res<ButtonInput<KeyCode>>,
     ship: Single<(&Transform, &physics::Velocity), With<Ship>>,

src/machinery.rs

@@ -1,5 +1,8 @@
-//! These are Systems that power the main game mechanics (and some misc items to support them)
+//! Systems, Components, and any other items for powering the game logic.
-
+//!
+//! Where the objects (ship, asteroid, etc) carry their own behavioral systems,
+//! the *game* keeps its main logic here. Its for ambient behaviors, like
+//! asteroid spawning, or eventually the flying saucer spawns.
 use rand::{Rng, SeedableRng};
 use std::time::Duration;
 
@@ -7,6 +10,12 @@ use bevy::prelude::*;
 
 use crate::{WorldSize, events::SpawnAsteroid, objects::AsteroidSize};
 
+/// Asteroid spawning parameters and state.
+///
+/// This struct keeps track of the rng and timer for spawning asteroids. In the
+/// future it may contain additional fields to allow for more control.
+///
+/// It's values are operated by the [`tick_asteroid_manager`] system.
 #[derive(Resource)]
 pub struct AsteroidSpawner {
     rng: std::sync::Mutex<rand::rngs::StdRng>,
@@ -26,8 +35,8 @@ impl AsteroidSpawner {
     }
 }
 
-/// Update the asteroid spawn timer and spawn any asteroids
+/// Update the asteroid spawn timer in the [`AsteroidSpawner`] resource, and
-/// that are due this frame.
+/// spawns any asteroids that are due this frame.
 pub fn tick_asteroid_manager(
     mut events: EventWriter<SpawnAsteroid>,
     mut spawner: ResMut<AsteroidSpawner>,
@@ -46,7 +55,7 @@ pub fn tick_asteroid_manager(
         let spawn_angle = rng.random_range(0.0..(std::f32::consts::PI * 2.0));
         // Rho will be the radius of a circle bordering the viewport, multiplied by 1.2
         // TODO: Use view diagonal to get a minimally sized circle around the play area
-        let spawn_distance = play_area.width.max(play_area.height) / 2.0;
+        let spawn_distance = play_area.x.max(play_area.y) / 2.0;
 
         // Convert polar to Cartesian, use as position
         let pos = Vec2::new(
@@ -77,9 +86,11 @@ pub fn tick_asteroid_manager(
     }
 }
 
+/// Sets a lifetime on an entity to automatically delete it after expiration.
 #[derive(Component)]
 pub struct Lifetime(pub Timer);
 
+/// System to tick the [`Lifetime`] timers and despawn expired entities.
 pub fn tick_lifetimes(
     mut commands: Commands,
     time: Res<Time>,

src/objects.rs

@@ -28,6 +28,7 @@ use crate::{
     physics::{Velocity, Wrapping},
 };
 
+/// The asteroid, defined entirely by [it's size](`AsteroidSize`).
 #[derive(Component, Deref, DerefMut)]
 pub struct Asteroid(pub AsteroidSize);
 
@@ -39,6 +40,8 @@ pub enum AsteroidSize {
 }
 
 impl AsteroidSize {
+    /// Convenience util to get the "next smallest" size. Useful for splitting
+    /// after collision.
     pub fn next(&self) -> Option<Self> {
         match self {
             AsteroidSize::Small => None,
@@ -48,9 +51,11 @@ impl AsteroidSize {
     }
 }
 
+/// Marker component for the player's ship.
 #[derive(Component)]
 pub struct Ship;
 
+/// Marker component for bullets.
 #[derive(Component)]
 pub struct Bullet;
 
@@ -126,6 +131,11 @@ pub fn split_asteroids(
     }
 }
 
+/// Spawns the player at the world origin. Used during the state change to
+/// [`GameState::Playing`] to spawn the player.
+///
+/// This only spawns the player. For player **re**-spawn activity, see the
+/// [`ship_impact_listener()`] system.
 pub fn spawn_player(mut commands: Commands, game_assets: Res<GameAssets>) {
     commands
         .spawn((
@@ -160,6 +170,9 @@ pub fn bullet_impact_listener(mut commands: Commands, mut events: EventReader<Bu
 
 /// Watch for [`ShipDestroy`] events and update game state accordingly.
 ///
+/// One life is taken from the counter, asteroids are cleared, and the player
+/// is placed back at the origin. If lives reach 0, this system will change
+/// states to [`GameState::GameOver`].
 /// - Subtract a life
 /// - Check life count. If 0, go to game-over state
 /// - Clear all asteroids

src/physics.rs

@@ -1,5 +1,19 @@
 //! Custom physics items
+//!
 //! TODO: Refactor in terms of Rapier2D, *or* implement colliders and remove it.
+//!
+//! Position, both translation and rotation, are tracked by the built-in
+//! Bevy [`Transform`] component. This module adds a (Linear) [`Velocity`] and
+//! [`AngularVelocity`] component to the mix.
+//! These two components are operated by simple integrator systems to
+//! accumulate translation and rotation from the velocities.
+//!
+//! The [`Wrapping`] component marks things that should wrap around the world
+//! boundaries. It's a kind of physical property of this world, so I'm putting
+//! it here.
+//!
+//! Collisions are also considered physics. After all, I got *a physics engine*
+//! to detect them for me (so that I don't have to write clipping code).
 
 use crate::{
     WorldSize, events,
@@ -42,9 +56,9 @@ pub(crate) fn wrap_entities(
     mut query: Query<&mut Transform, With<Wrapping>>,
     world_size: Res<WorldSize>,
 ) {
-    let right = world_size.width / 2.0;
+    let right = world_size.x / 2.0;
     let left = -right;
-    let top = world_size.height / 2.0;
+    let top = world_size.y / 2.0;
     let bottom = -top;
 
     for mut pos in query.iter_mut() {

src/resources.rs

@@ -10,7 +10,7 @@ use bevy::{
         Vec2,
         primitives::{Circle, Triangle2d},
     },
-    prelude::{Deref, Reflect, ReflectResource},
+    prelude::{Deref, DerefMut, Reflect, ReflectResource},
     render::mesh::Mesh,
     sprite::ColorMaterial,
 };
@@ -19,7 +19,7 @@ use bevy_inspector_egui::inspector_options::ReflectInspectorOptions;
 
 use crate::{
     ASTEROID_SMALL_COLOR, BULLET_COLOR, PLAYER_SHIP_COLOR, SHIP_THRUSTER_COLOR_ACTIVE,
-    SHIP_THRUSTER_COLOR_INACTIVE,
+    SHIP_THRUSTER_COLOR_INACTIVE, config::WINDOW_SIZE,
 };
 
 #[derive(Resource, Debug, Deref, Clone, Copy)]
@@ -41,10 +41,13 @@ impl From<Lives> for String {
     }
 }
 
-#[derive(Resource)]
+#[derive(Deref, DerefMut, Resource)]
-pub struct WorldSize {
+pub struct WorldSize(Vec2);
-    pub width: f32,
+
-    pub height: f32,
+impl Default for WorldSize {
+    fn default() -> Self {
+        WorldSize(Vec2::new(WINDOW_SIZE.x, WINDOW_SIZE.y))
+    }
 }
 
 #[derive(Resource)]

src/widgets.rs

@@ -1,34 +1,81 @@
 use crate::{
     GameState,
+    config::{UI_BUTTON_HOVERED, UI_BUTTON_NORMAL, UI_BUTTON_PRESSED},
     resources::{Lives, Score},
 };
 
 use bevy::{
-    color::palettes::css::{BLACK, GREEN, LIGHT_BLUE, RED},
+    color::palettes::css::{BLACK, DARK_GRAY, GREEN, LIGHT_BLUE, RED, WHITE},
     prelude::*,
 };
 
-pub fn spawn_ui(mut commands: Commands, score: Res<Score>, lives: Res<Lives>) {
+/// Plugin for the main menu
-    commands.spawn((
+pub struct PluginGameMenu;
-        Text::new(format!("Score: {score:?} | Lives: {lives:?}")),
+
-        TextFont::from_font_size(25.0),
+impl Plugin for PluginGameMenu {
-    ));
+    fn build(&self, app: &mut App) {
+        app.add_systems(OnEnter(GameState::TitleScreen), spawn_menu)
+            .add_systems(OnExit(GameState::TitleScreen), despawn::<MarkerMainMenu>)
+            .add_systems(
+                Update,
+                (handle_spacebar, operate_buttons).run_if(in_state(GameState::TitleScreen)),
+            );
+    }
 }
 
-pub fn preparation_widget_plugin(app: &mut App) {
+/// Plugin for the "get ready" period as gameplay starts.
+pub struct PluginGetReady;
+
+impl Plugin for PluginGetReady {
+    fn build(&self, app: &mut App) {
         app.add_systems(OnEnter(GameState::GetReady), spawn_get_ready)
-        .add_systems(OnExit(GameState::GetReady), despawn_get_ready)
+            .add_systems(OnExit(GameState::GetReady), despawn::<OnReadySetGo>)
             .add_systems(
                 Update,
                 (animate_get_ready_widget).run_if(in_state(GameState::GetReady)),
             )
             .insert_resource(ReadySetGoTimer(Timer::from_seconds(3.0, TimerMode::Once)));
+    }
 }
 
+/// Plugin for the game-over screen
+pub struct PluginGameOver;
+
+impl Plugin for PluginGameOver {
+    fn build(&self, app: &mut App) {
+        app.add_systems(OnEnter(GameState::GameOver), spawn_gameover_ui)
+            .add_systems(OnExit(GameState::GameOver), despawn::<MarkerGameOver>)
+            .add_systems(
+                Update,
+                operate_buttons.run_if(in_state(GameState::GameOver)),
+            );
+    }
+}
+
+// Marker component for the title screen UI entity.
+// This way, a query for the TitleUI can be used to despawn the title screen
+#[derive(Component)]
+struct MarkerMainMenu;
+
 /// Marker component for things on the get-ready indicator
 #[derive(Component)]
 struct OnReadySetGo;
 
+/// Marker for things on the game-over screen
+#[derive(Component)]
+struct MarkerGameOver;
+
+/// Action specifier for the game-over menu's buttons.
+///
+/// Attach this component to a button and [`PluginGameOver`] will use it to
+/// decide what to do when that button is pressed.
+#[derive(Component)]
+enum ButtonMenuAction {
+    ToMainMenu,
+    StartGame,
+    Quit,
+}
+
 /// Newtype wrapper for `Timer`. Used to count down during the "get ready" phase.
 #[derive(Deref, DerefMut, Resource)]
 struct ReadySetGoTimer(Timer);
@@ -41,6 +88,70 @@ struct CountdownText;
 #[derive(Component)]
 struct CountdownBar;
 
+/// Despawns entities matching the generic argument. Intended to remove UI
+/// elements.
+fn despawn<T: Component>(mut commands: Commands, to_despawn: Query<Entity, With<T>>) {
+    for entity in to_despawn {
+        commands.entity(entity).despawn();
+    }
+}
+
+/// Utility function for creating a standard button.
+fn button_bundle(text: &str) -> impl Bundle {
+    (
+        Button,
+        // TODO: Generic action
+        Node {
+            width: Val::Px(150.0),
+            height: Val::Px(65.0),
+            border: UiRect::all(Val::Px(2.0)),
+            justify_content: JustifyContent::Center,
+            align_items: AlignItems::Center,
+            margin: UiRect::all(Val::Px(5.0)),
+            ..default()
+        },
+        BorderColor(Color::BLACK),
+        BorderRadius::MAX,
+        BackgroundColor(UI_BUTTON_NORMAL),
+        children![(
+            Text::new(text),
+            TextColor(Color::srgb(0.9, 0.9, 0.9)),
+            TextShadow::default(),
+        )],
+    )
+}
+
+fn spawn_menu(mut commands: Commands) {
+    commands
+        .spawn((
+            MarkerMainMenu,
+            Node {
+                width: Val::Percent(100.0),
+                height: Val::Percent(100.0),
+                align_items: AlignItems::Center,
+                justify_content: JustifyContent::Center,
+                flex_direction: FlexDirection::Column,
+                ..Default::default()
+            },
+        ))
+        .with_children(|cmds| {
+            cmds.spawn((
+                Text::new("Robert's Bad Asteroids Game"),
+                TextFont::from_font_size(50.0),
+                TextLayout::new_with_justify(JustifyText::Center),
+                TextShadow::default(),
+            ));
+            cmds.spawn((
+                Text::new("Press space to begin"),
+                TextFont::from_font_size(20.0),
+                TextColor(Color::srgb(0.7, 0.7, 0.7)),
+                TextShadow::default(),
+            ));
+            cmds.spawn((button_bundle("Start Game"), ButtonMenuAction::StartGame));
+            cmds.spawn((button_bundle("Quit"), ButtonMenuAction::Quit));
+        });
+}
+
 fn spawn_get_ready(mut commands: Commands) {
     commands.spawn((
         OnReadySetGo, // marker, so this can be de-spawned properly
@@ -75,12 +186,25 @@ fn spawn_get_ready(mut commands: Commands) {
     ));
 }
 
-// TODO: Replace this with a generic somewhere else in the crate
+/// Spawns the game over screen.
-// want: `despawn_screen::<OnReadySetGo>>()`
+///
-fn despawn_get_ready(mut commands: Commands, to_despawn: Query<Entity, With<OnReadySetGo>>) {
+/// Used by [`PluginGameOver`] when entering the [`GameState::GameOver`] state.
-    for entity in to_despawn {
+fn spawn_gameover_ui(mut commands: Commands) {
-        commands.entity(entity).despawn();
+    commands.spawn((
-    }
+        MarkerGameOver, // Marker, so `despawn<T>` can remove this on state exit.
+        Node {
+            width: Val::Percent(100.0),
+            height: Val::Percent(100.0),
+            align_items: AlignItems::Center,
+            justify_content: JustifyContent::Center,
+            flex_direction: FlexDirection::Column,
+            ..default()
+        },
+        children![
+            (button_bundle("Main Menu"), ButtonMenuAction::ToMainMenu,),
+            (button_bundle("Quit"), ButtonMenuAction::Quit),
+        ],
+    ));
 }
 
 fn animate_get_ready_widget(
@@ -108,53 +232,70 @@ fn animate_get_ready_widget(
     }
 }
 
-pub struct GameMenuPlugin;
+/// Handles interactions with the menu buttons.
-
+///
-impl Plugin for GameMenuPlugin {
+/// The buttons are used by the main menu and the game-over menu to change
-    fn build(&self, app: &mut App) {
+/// between game states.
-        app.add_systems(OnEnter(GameState::TitleScreen), spawn_menu)
+///
-            .add_systems(OnExit(GameState::TitleScreen), despawn_menu)
+/// Button animation and action handling is done entirely within this system.
-            .add_systems(
+///
-                Update,
+/// There are no checks for current state. If a "quit" button was put somewhere
-                handle_spacebar.run_if(in_state(GameState::TitleScreen)),
+/// on the HUD, this system would quit the game. The same will happen for
-            );
+/// returning to the title screen. This should be useful for making a pause
-    }
+/// menu, too.
-}
+fn operate_buttons(
-
+    mut interactions: Query<
-// Marker component for the title screen UI entity.
+        (
-// This way, a query for the TitleUI can be used to despawn the title screen
+            &Interaction,
-#[derive(Component)]
+            &mut BackgroundColor,
-struct TitleUI;
+            &mut BorderColor,
-
+            &ButtonMenuAction,
-fn spawn_menu(mut commands: Commands) {
+        ),
-    commands
+        (Changed<Interaction>, With<Button>),
-        .spawn((
+    >,
-            TitleUI,
+    mut game_state: ResMut<NextState<GameState>>,
-            Node {
+    mut app_exit_events: EventWriter<AppExit>,
-                flex_direction: FlexDirection::Column,
+) {
-                ..Default::default()
+    // TODO: Better colors. These are taken from the example and they're ugly.
-            },
+    for (interaction, mut color, mut border_color, menu_action) in &mut interactions {
-        ))
+        match *interaction {
-        .with_children(|cmds| {
+            Interaction::Pressed => {
-            cmds.spawn((
+                *color = UI_BUTTON_PRESSED.into();
-                Text::new("Robert's Bad Asteroids Game"),
+                border_color.0 = DARK_GRAY.into();
-                TextFont::from_font_size(50.0),
+                match menu_action {
-            ));
+                    ButtonMenuAction::ToMainMenu => {
-            cmds.spawn((
+                        game_state.set(GameState::TitleScreen);
-                Text::new("Press space to begin"),
+                    }
-                TextFont::from_font_size(40.0),
+                    ButtonMenuAction::StartGame => {
-            ));
+                        game_state.set(GameState::Playing);
-        });
+                    }
-}
+                    ButtonMenuAction::Quit => {
-
+                        app_exit_events.write(AppExit::Success);
-fn despawn_menu(mut commands: Commands, to_despawn: Query<Entity, With<TitleUI>>) {
+                    }
-    for entity in &to_despawn {
+                }
-        commands.entity(entity).despawn();
+            }
+            Interaction::Hovered => {
+                *color = UI_BUTTON_HOVERED.into();
+                border_color.0 = WHITE.into();
+            }
+            Interaction::None => {
+                *color = UI_BUTTON_NORMAL.into();
+                border_color.0 = BLACK.into();
+            }
+        }
     }
 }
 
+/// Main menu input listener. Starts game when the spacebar is pressed.
 fn handle_spacebar(input: Res<ButtonInput<KeyCode>>, mut game_state: ResMut<NextState<GameState>>) {
     if input.just_pressed(KeyCode::Space) {
         game_state.set(GameState::GetReady);
     }
 }
+
+pub fn spawn_ui(mut commands: Commands, score: Res<Score>, lives: Res<Lives>) {
+    commands.spawn((
+        Text::new(format!("Score: {score:?} | Lives: {lives:?}")),
+        TextFont::from_font_size(25.0),
+    ));
+}