I've beaten the game on Normal/Bacteria (after a gajillion tries). Much to my disappointment it didn't unlock the next type, "virus" nor did it give me the achievement. Has anyone experienced this?
I think your problem is that you are killing people too fast and not actually winning - i.e. people die before they can pass on the infection to other people. The game ends when there are no infected people left. Are you getting a blue 'defeat' screen or a red 'victory' screen? If it is blue - make sure there are not any sneaky healthy people hiding!
