My current side project is a transparent application (that sits on your taskbar) idle/management game and I realized I can play it at the same time as my main creature collecting game. Why? Why not?
The game itself is pretty simple - dinosaurs work out on the bottom of your screen on equipment that you buy. Dinos gain stats and level up as they exercise and you can send them off to competitions where they can win medals which in turn unlock the ability to upgrade your gym with new equipment and decorations with global buffs (along with some purely cosmetic features like flooring and paints).