Winter!: Prepare for holiday gaming!
This challenging game is actually several very simple games strung together as levels. The challenge comes from the abrupt change from one simple game to another as you evolve into a new creature with new challenges. As a protozoa, all you can do is move around the screen. As a beaver, you have to build a dam without getting eaten. As a gorilla, you have to thow fruit at monkeys who are much more agile than you are. There are other creatures between these, each with different problems and gameplay specifics.
Eventually, you get to play a Human who has a gun and a screen full of monsters to shoot. Beat that level, and you see a mushroom cloud, and you're back to square one as a protozoa.
Any of these games could have been successful on their own just a few years before Evolution was released. Together, as levels in a larger game, with no time to adjust to new controls and tactics between levels, they become quite a challenge.
Game Traits applied to Evolution (APL2) by LordXenophon