I once had a game on my PC, which I remembered because I finally saw the game, Spore. (yes living under a rock) anyway...

In this game, there is a black background, there are cells which are generated. You can feed the cells or attack them, and these float across the screen either attacking other cells and killing them, or mating with them to produce evolved cells. Basically, the cells grow and then split, or the mutate making different cells.

The graphics are just lines, so it has the feel of one of those doom map editors....

Hope someone might have a clue what I'm on about??