This is a nice little game! Short and sweet with an interesting design. The sprites were cute and the animation was pretty good.
I would have liked a bit more in-game guidance, especially with the DNA powerups. I used one at the station without realizing that it is only effective for one room so I had to start over. I wasn't a big fan of the controls; I think it would have been much easier with something like z,x,c and the arrow keys. Several times I accidentally moved the mouse outside the small window and wasn't able to attack. There were also some visibility issues, like when the health bar blocks the exit to the upper room.
Overall I like the idea and I think this has some great potential. Thanks for sharing.