Worked fine for me on Firefox. I agree with some comments suggesting a fast-forward button. Watching a wave of "slow" walk across the screen to the towers isn't gripping!! Finding it very hard to get ranged scraps - I don't know if thats just me though? Making evolving hard
Any risk of a slightly less depressing ending than making us feel like mass murduers of small cute pixel animals all for nothing? :'( :'( [I know thats the point but still]
FYI: Speed-up functionality was JUST added!