I recently got into ROM hacks, namely Super Mario World, and to quench my thirst to make games about as hard as most 1980s NES games, I've decided to craft Super Mario Underworld.

Plot: Mario has been summoned into the Hell-end of purgatory and his job is to kill this unknown entity and get himself out alive. Good thing the netherworld tries all it can to keep that form happening!

I'm doing the full monty, overworld changes, palette swaps, an overhaul on that Disney ass music, with hair ripping difficulty tested by yours truely.
I'll also throw in some puzzles, make you think.
The Yellow Switch palace is a good example.

Forcing you to come in with a cape to survive then forces you to get rid of it, so you'll be small enough to get by and press the switch.
So you'll have to backtrack and get the cape and walk by through the stage to know what happens next.
I also added in some infinity holes, that if you fall in them, you must either reset the game, kill yourself (if possible MUAHAHAHAHA) or let the time run out.

I'm in early development, but it's oh so fun.
I guess I can release a demo once I get to the first castle, I'd like others to try it, but be warned.
It's not for those who give up easily.