Neat Idea. I wanted to be able to use the 1 2 3 4 5 keys to control the cells. I think if you did that you'd be able to ramp the difficulty up. I was able to get to 37 hours with out trouble and it didn't seem to be getting any hard so I left it there. Lots of room to expand this with different things you need to keep track of and deal with. Would love to see more of this.