corrections

src/camera.rs

@@ -3,14 +3,17 @@ use bevy::prelude::*;
 use crate::player::Player;
 use crate::player::move_player;
 
-fn spawn_camera(mut commands: Commands) {
-    commands.spawn(Camera2d);
+#[derive(Component)]
+pub struct MainCamera;
+
+fn spawn_main_camera(mut commands: Commands) {
+    commands.spawn((Camera2d, MainCamera));
 }
 
 // Follow the player with the camera
 fn follow_player(
-    player: Single<&Transform, (With<Player>, Without<Camera2d>)>,
-    mut camera: Single<&mut Transform, (With<Camera2d>, Without<Player>)>,
+    player: Single<&Transform, (With<Player>, Without<MainCamera>)>,
+    mut camera: Single<&mut Transform, (With<MainCamera>, Without<Player>)>,
     // time: Res<Time>,
 ) {
     camera.translation.y = player.translation.y; // without delay
@@ -22,7 +25,7 @@ pub struct CameraPlugin;
 
 impl Plugin for CameraPlugin {
     fn build(&self, app: &mut App) {
-        app.add_systems(Startup, spawn_camera)
+        app.add_systems(Startup, spawn_main_camera)
             .add_systems(Update, follow_player.after(move_player));
     }
 }