Final Idea: Tower Offense
The player controls rogue cells which must make their way to the heart. The player can only control when the cells are released into the bloodstream, and evolve the cells from collected DNA. DNA can be found occasionally, and can also be collected from neutralized white blood cells.
Rogue Cells:
Bacteria – high speed, low firepower, low protection
Parasite – a cell which can latch on to white blood cells and destroy them from the inside. They can be destroyed by nearby white blood cells. medium speed, no firepower, low protection
Tumor – a cell which moves slowly but has high protection from white blood cells and protects any cells behind it. low speed, no firepower, high protection
Virus – a cell which breaks into two Virus Spawn when attacked. medium speed, medium firepower, no protection
Virus Spawn – medium speed, medium firepower, low protection