There was a video game that was like Smash Bros, except, the fighters were characters from different indie series / franchises, such as FNAF, Bendy, Spooky's Jumpscare Mansion, BFDI, Digital Circus, Uncle Samsonite, Roblox games, Poppy Playtime, Murder Drones, Baldi's Basics, etc.

I bet that would be peak.