Hey Golds,
Cool game. I thought the music/style was funny and that the graphics were very well done (especially considering how long you had to do it). About the game itself, the idea of flying around as a mosquito is interesting and fun (even if only for the weirdness of it all), but I really couldn't feel that the way I was flying had any influence on my success as a parasite.
For instance, I was trying to come from behind, as a "stealthy" mosquito, but it didn't help my survival ratio very much. The best strategy I've found was dropping at full speed on someone, sucking blood for a few seconds (before they got angry) and then jumping to the next target.
If I had to guess what your algorithm is, I'd say you spawn every human with a counter for patience and rate for recovering patience. Then, if the mosquito is within "x" units from the human, you remove patience from that human. If a human's patience ends (patience is below zero, or something), the human gets angry and attacks with slaps and DDT. While that is a valid mechanic, the lack of a "flying skill" to learn reduces the game's replayability.
While the game is cool as it is, I'd make a few changes:
1) Somehow add a "noise" factor into the game, so you can reward stealthy players and skillful flying / landing.
2) Add wind. That should make flying a bit harder, too.
3) Make the "air space" larger. Those bats are really hard to dodge, and the DDT has such a long range that it's almost impossible to evade.