Coins, Combos & Stomping
The Proving Grounds
Lesson 1
Collectible Coins
Build: An Area2D pickup with real juice

Lesson 2
Combos & the Score HUD
Build: Track score, decay a combo, pop the label

Lesson 3
The Stompable Enemy
Build: One Hitbox decides stomp vs hurt

Lesson 4
Death & Respawn
Build: One die(), one killzone, instant respawn
