Interesting and easy to pick up
This is a really interesting game. The graphics are pretty nice and the controls are easy as pie. At first it's slow, but quickly speeds up and becomes a real challenge. With an abundance of cells and germs, however, comes some noticeable lag. I think you need to try to reduce the lag in later levels a bit. It's nothing that'll kill the fun, but it's a little annoying.
The upgrades are pretty unique and can really be used to fit the player's strategy. A player who wants to do things quick can use latency, whereas a player who wants to build an army can use reproduction and so on and so forth. They're all pretty balanced, too.
There's one but I encountered, but it only happens on the first level so it's no biggie after that. I didn't know what I was doing, so I managed to lose the first level by infecting a cell too far to the bottom. The result was that I was at level NaN with NaN EP and proceeding to the next level resulted in an automatic victory. In other words, I had to start a new game to fix it. Of course this only happens on the first level, so it's far from damaging to gameplay beyond that point.
Overall this game is very, very interesting. It's a neat concept and the game itself is incredibly easy to pick up. Great job.