Serum Game Concept

Starting with the Cube Engine by WVO - because it's codebase is tiny, and it'll likely do the job

Aliens vs Humans, but blood is the weapon against the other race (Hence Serum weapons patched into user)

If serum of both types combine on a surface, a new being evolves (The Serumoid)

These serumoid's are intelligent, and although they only can become 6 parts (Bone, Wing, Knuckle, Eye, Skin or Tooth), they can combine to form fearsome, problem solving creatures that will absorb any being they contact - alien or human. Serumoids can only be killed with a massive percentage of a single serum type. A health meter-style will help this. Multiple serum types will simply make it bigger and stronger.

Fight neat, kill with accuracy, or the Serumoids kill everyone...

Well, that's the rough idea, anyway...

BUILDING: You will need gl.h: sudo apt-get install libglu1-mesa-dev