Okay, weird bug I found just now. if you go into a loading zone right after you fall into a pit you become microscopic. Currently beating the game in (literal) baby mode.
The game actually runs the same, but I'm just small. The lantern still spins and launches, albeit without the chain, and the light doesn't conform to my smaller size.
Baby Mode honestly sounds really funny tho, so I might try it myself! Reminds me of secret modes in '90s games, like ones that made your character's head gigantic. <3