I like it!
I remember this from FGL, though... :)
Maybe some more action-ey music in the actual game might have been better.
White blood cells would have been cool. Maybe some more weapons than a chemical bomb.
What if you progressed through the body and laid eggs or something. When they hatched, you would have more buddies.
I read somewhere that bacteria propel themselves by a chemical motor... mayber
Also, i read somewhere that bacteria can propel themselves using chemical motors... maybe you could add a speed boost type thing.
Over all, pretty good!