It's ok
This was a well animated, well programmed game that could use a bit of work in the playability department
I really enjoyed the premise of the game, voyaging into the human body (as opposed to traversing untold parsecs fighting nameless alien drones) was kind of a unique, albeit a bit contrived twist. That area could have been fleshed out, in story and mechanics, to add to the game world.
The animation and control was, as far as I saw, flawless. There was a bit of an issue switching to full screen and back again where I lost control for a minute, but that's only a minor thing and really didn't detract from the gameplay - probably going to be technical issues there regardless of the skill of the programmer.
One major flaw I found was the inability to switch formations. From the reviews that I read (just a few) it would seem that this was a major innovation for the game. However, I was unable to switch at all. I hit all the number keys multiple times, while firing and while still, keyboard and numberpad, and yet I still remained in the single tight circling formation. This sounds like a great concept if executed correctly, but alas I must chalk this up to a game bug or programming flaw (maybe compatibility with firefox, possibly?).
Upgrades would have been great, as it does get a bit monotonous just firing the same thing and moving around fighting brain cells or whatnot. The possibilities here are vast, for sure. Neural toxins, electrical shocks, parasites/bacteria carried by the ladybug to name a few - the possibilities are vast, and many mechanics from basic shooters could be incorporated into this environment with relative ease.
As fantasy dragon pointed out, a Pause option would be great. Also, the game does tend to drag on a bit, but powerups or a bit more variety in the enemies/object to fight would have livened this up significantly. That being said, I found your comments on FD's review pretty ironic. I hope you find this review actually constructive and critical, as I enjoyed it for a while, but didn't find alot of replay value.
With a few tweaks this could be a great game. As it stands, however, I believe that it's destined for obscurity. In any case, please give us more. Give us some innovation and originality while maintaining your quality of art and gameplay.
Thanks.