If you still feel like trying out the game, the grey and can only be beaten with a flick. To flick unequip the gun with space and hold down the left mouse button to charge up a flick!
Ahh, that makes sense! Okay I gave it another go. I like the additional attack option(still died due to the four grey ants protecting the swarm or red ants, but now I know how to fight them). The gun is better but this adds some good variety! Sound effects are spot on.