What about playing with an existing game engine, and learning to make mods, modifying the game logic through it's scripting language, playing with textures, models, etc.
I started programming in qbasic, as a kid, and got into making mods for Quake. The scripting language designed for it (QuakeC) was really how I first came into contact with anything resembling C, and it was only a while later that I started making my first rainbow triangles and texturing them using OpenGL and a C compiler.