This is a GitHub hosted tutorial based on building Level 3 from the game Reincarnage. The game is all about spiders eating frogs, and frogs eating flies and so on. You get to play what you eat each level! The game is a combination of a platformer and a free-fall game.
This tutorial covers building the game step-by-step. You can paste in each piece of code, refresh and see the changes immediately. It's a nice way of learning how the game is built-up layer by layer.