A game by the name of "Entering the Fuckbear Door".

Or possibly "Returning to the Fuckbear Door".

Or both, idk and idc at this point.

All I do know is this was the closest to what I was looking for in terms of what the fangame was.

Basically, It was a BIG mess, though I only remember playing a bit where I was fighting doors (yes, really), as withered chica, and then fighting goofy. Then I never played it again because IDK.

I also didn't save it because IDK. Oof.

Edit: as it turns out, whoever made the games had 4 of the "Fuckbear Door" Games, and also still has a gamejolt account. Huh.