This game could be accurate if the virus was a RNA virus and a new hybrid. The antibiotics could be inhibitors of RNA transcriptase, and if the virus was a RNA virus this would be semi-effective in killing the viruses as seen in game with the increased resistance (much like how the aids virus , which is treated with cocktails of such inhibitors and enzymes with similar effects). However on the other hand the cells have no DNA, as they are red blood cells, so in order for the virus to be effective it would need to talk directly to the ribosomes, or inject an RNA segment that was able to be transcribed into a protein that could assemble new RNA strips and old to create more of such protein. But this would mean the "antibiotic" would have to destroy said protein or have enzymes that recognize these RNA segments (siRNAs could also be effective). In conclusion this game could be correct if the virus was a hybrid RNA virus and the "antibiotics" where of the previously stated nature.
my only problems are its gets boring, the machine gun does not auto fire when mouse is down, lack of auto turrets, and the shotgun burst is the same as the machine guns.