After around level 10 I found that the player can become incredibly overpowered, by choosing quicker DNA if it is available.
You have some nice ideas, for instance, at the start it seemed like it was going to be a game of reflexes against the invading enemy cells, this element dissipates around the level 10 mark, as I previously said. If you sustained the difficulty as the player gains levels and reward them in other areas to representation, the game would consistently be fun.
There is much potential for the various mechanics you have incorporated here, overall this is a good job. The graphics work well in the games favor, everything is easy to see and understand.
Good game with much promise.