Platypus Evolution is a simple game in the style of Cookie Clicker or adVenture Capitalist where you have to create a platypus farm, getting most of your income from... platypus poop.
The game system in Platypus Evolution is very simple: every 10 seconds, a box with a new platypus arrives. When you combine two of them, you create a big platypus, with two big ones you can create a mutant platypus, with two mutants a super mutant, and then a mammoth platypus, and so on.
The more evolved a platypus, the more money you can get from its poop. You can use that money to buy all types of upgrades for your farm, so you earn more money with less effort. The tractor, for instance, lets you get money without having to be in front of your device.
Platypus Evolution is a simple casual game, and as with all titles of this kind, it's entertaining and addictive. It also has nice graphics.