Gold becomes totally useless after a certain point in the game--it doesn't accumulate fast enough to be useful for forcing mutations, even if you leave the game on 24/7. I'd also appreciate some way to buy previously-archived mutations, so that if you forget to save a clover for breeding at a high level, you don't have to breed all the way up from level 1. Aside from that, this is a clever and oddly addictive idle game.
Strangely addictive. I feel like I'm being tricked into learning chemistry, which is not actually a bad feeling. It might be nice if it were made explicit what the chances are of a natural selection try being successful, and as another reviewer suggested, if the rewards for completing an era were a little more compelling. That said, I really like the game, and especially the "knowledge" component. It adds a motivation to extract elements that aren't normally used in compounds to gain an overall bonus.
 "Ultimate Five-Leaf Clover"){kind=icon}
 "Idle Evolution"){kind=icon}
 "Pandemic 2"){kind=icon}