Fantastic
That was a great game. It kept me interested and had me develope basic strategy to actually progress. I hope your later games are a little more involved. Perhaps progressing through the blood stream to incorporate different shaped blood vessels, or even changing levels at times to clear out a major organ that has been infected(somewhat like a boss battle) , fixing the range of your attacks or allowing for upgrades. One major flaw I found was you couldn't shoot past the virus cells that you had already shot, preventing many times from hitting others.