I like it...
...but I'm really bad at it.
The controls are good and the interface is clean. Though you mention "correct ratio" in order to consume other enemy microbes, I feel allowing a little more leeway on that would be nice. Or, perhaps, allow for you to grow a much larger microbe because when the enemy splits and eats one protein, I'm kind of stuck until they split again.
...or maybe I'm just playing it wrong. Good stuff though.