Add project files.

AlientAttack.MonoGame/Things/Bullets/Bullet.cs

@@ -0,0 +1,51 @@
+using AlienAttack.MonoGame.Things.Items;
+
+namespace AlienAttack.MonoGame.Things.Bullets;
+
+internal class Bullet(float x, float y, float xVel, float yVel, Sprite owner) : Sprite(x, y)
+{
+    protected float XVelocity = xVel;
+    protected float YVelocity = yVel;
+    public Sprite Owner { get; protected set; } = owner;
+    public int Damage { get; protected set; } = 0;
+
+    public override void Draw(SpriteDrawArgs args)
+    {
+        base.Draw(args);
+    }
+
+    public override void Update(SpriteUpdateContext context)
+    {
+        XPosition += XVelocity;
+        YPosition += YVelocity;
+
+        if (XPosition + BoundBox.Width < 0
+            || XPosition > context.ViewTransform.ScreenWidth
+            || YPosition + BoundBox.Height < 0
+            || YPosition > context.ViewTransform.ScreenHeight)
+        {
+            IsDead = true;
+        }
+
+        base.Update(context);
+    }
+
+    public override void OnCollision(SpriteCollisionContext context)
+    {
+        if (context.Sprite is Bullet || context.Sprite == Owner || context.Sprite is Item)
+            return;
+
+        IsDead = true;
+
+        float xVel = 0;
+        float yVel = 0;
+
+        if (context.Sprite is MoveableSprite moveableSprite)
+        {
+            xVel = moveableSprite.XVelocity;
+            yVel = moveableSprite.YVelocity;
+        }
+
+        context.SpawnSprite(new MiniExplosion((int)XPosition, (int)YPosition, xVel, yVel));
+    }
+}