Did you forgot to add "Occusion Culling"? Because my pc was like burning A LOT. There is no pixel perfect in main menu, using same song in main menu and gameplay (i saw that, correct me if im wrong). Otherwise its good game!
Viewing post in Project Greed jam comments
I fixed the performance issues, it turned out it was continuous collision detection on the coins :D Now the coins sometimes get stuck in walls, but I can live with that :D Play.unity.com