A harder version of SMW?
It probably wouldn't be a good idea unless you can make it actually enjoyable by basing yourself off of the original levels and pulling off your own twist (as long as nothing is unchanged), just like
Loop2. You can go wild, but make sure it's possible to beat.
"Harder" and "painful" in what sense? Assuming you mean convoluted and intricate, then you could experiment a lot with objects and sprites. You can take advantage of some resources over their respective sections (the
sprites on platforms patch is a perfect example, but it involves SA-1). Some hacks make good usage of them, so be sure to check them in the hacks section or in this very subforum regularly. Puzzles involving blocks and enemies are your best bets as well. It's up to you, but don't just make it a muncher obstacle course with jumping precision.
That name is quite blatant, but then again I can't think of a better one myself...
On the other hand, why would you want NSFW content to show up in your hack? lol
Windowless ride, feeling alive
Are you alive or just breathing?