Added setup system. Spawns two balls which are rendered correctly.

app/src/main.rs

@@ -1,7 +1,21 @@
-use bevy::prelude::*;
+use bevy::color::palettes::basic::RED;
+use bevy::prelude::*;                   // Core Bevy types
+
 
 fn main() {
     App::new()
         .add_plugins(DefaultPlugins)
+        .add_systems(Startup, setup)
         .run();
 }
+
+fn setup(mut commands: Commands, mut meshes: ResMut<Assets<Mesh>>, mut materials: ResMut<Assets<ColorMaterial>>) {
+
+    commands.spawn(Camera2d);
+
+    let shape =meshes.add(Circle::new(50.0));
+
+    commands.spawn((Mesh2d(shape.clone()), MeshMaterial2d(materials.add(Color::from(RED))), Transform::from_xyz(100.0, 0.0, 0.0)));
+
+    commands.spawn((Mesh2d(shape.clone()), MeshMaterial2d(materials.add(Color::from(RED))), Transform::from_xyz(0.0, 0.0, 0.0)));
+}