Made a lot more progress this evening:
- Crates now spawn in batches of X, created at Y-second intervals
- Each crate spawns at a random position between Y1 and Y2
- Crates move in one direction until they collide with the player
- On collision, the player’s animation changes
- The collided crate is destroyed, and a new one is spawned above with an offset
- The newly spawned crate moves in the opposite direction
