Been playing Mario quite a lot lately, and I've got a few things rattling around the ol' noggin that I thought might be worth sharing (or at least, it
was a few things before I started writing the post). Admittedly, the extend of my modding experience lies in Zandronum (Mega Man 8-bit Deathmatch, to be precise), so I don't know exactly what SRB2 is capable of, but there's no harm in stirring up some discussion, I trust.
- With the overalls and their unique coloration in mind, I wonder if it would at all be possible to toggle Mario's cap color as well. For instance, red cap and overalls with a blue shirt, classic style.
- It would be wonderful to play as both Mario & Luigi at once, like Sonic & Tails. It's been suggested to death already, and one could argue their differences aren't substantial enough to justify it, but even waaay back in Sonic 2, Tails didn't do anything special--he was just along for the ride.
- Reserve power-ups would be cool, and are something of a series staple besides. The Toss Flag button would probably be the ideal way to drop them. You could also use it to share power-ups in multiplayer!
- Going off of those last two suggestions, perhaps reserve power-ups could be used to justify a Luigi bot? For instance, he'd use or hold whatever power-up you have in reserve, and you could trade them at any time.
- For the special stages, it would be interesting to lean into the Super Mario Galaxy precedent set by Flying Mario. Rather than collecting spheres to bust open a capsule, maybe you're collecting star bits to feed a Hungry Luma? Or maybe just collecting purple coins? There's lots of possibilities.