klystron is a game engine that I’m writing for a Thrust remake. It includes a 2D sprite/tile graphics engine (with collisions), a tiny software synthesizer with music editor and level editor for editing tile maps. It’s written in C99 and uses SDL so it should be quite portable. The main emphasis is on performance and minimalism.
I split the game engine into two separate projects, the actual engine and related tools and the music editor (klystrack). This is because I think it’s fun to make tunes and have always wanter to code a tracker. Actually, klystrack has become the project that drives the engine development. You can read more about klystrack in my blog. Or, visit the Facebook page (neat stuff is posted there).