The final night would've been against Insane SpringBonnie (who was made into the main antagonist) and Springbonnie (renamed London Bridge).

It would've been at Cakebear's Bakery, and Cakebear himself was just a wooden stand on a track you would send to rooms to block off London Bridge.

All while Insane Springbonnie did wacky shit like boot you to a fake menu, randomly flip down your monitor when you flipped it up, and (my personal favorite) Anytime you were about to reach 6AM, he would rewind the clock back to 12.

This was only if you beat every night and got the good ending. Beating the minimum required nights would get you the bad ending, which lead to a 30 second, lame, boring night just against London Bridge. Obviously teasing that this wasn't the REAL final night.

Attached is the only surviving image of Cakebear before his file would be corrupted (sad!)

I'm still working on that AWESOME and SECRET fnaf project btw (Its not insanity related :( )