Arrow keys to move, tank controls. Simple noise function terrain, pyramid in the middle.
This uses a system where it steps along and calculates the height. Fancy terrain is generated using "Perlin Noise" (https://en.wikipedia.org/wiki/Perlin_noise), the fast noise is just a simple calculation I made. Feel free to remix and make your own games using this. A good challenge is to add a system for sprites to show up in the world, like characters and buildings.