Maybe the "Mario & Luigi" series of rpg platformers. You change between the brothers and their powers to solve puzzles.
Genesis version is the one I played, but didn't know about the extra levels. It's just my go-to system. I've tried the SNES version but didn't like the audio in comparison so didn't play it for very long.Time for a more serious answer - Fury of the Furries might be up your alley.
Also, which version of The Lost Vikings did you play? The Genesis port has a few extra levels that no other version has.
Yeah the "Norse by Norsewest" version seems ugly to me.Genesis version is the one I played, but didn't know about the extra levels. It's just my go-to system. I've tried the SNES version but didn't like the audio in comparison so didn't play it for very long.
I actually haven't played much of Lost Vikings 2. The SNES version looks a lot better visually than the others, mostly because it mimics the first game. I'll have to play both versions of that one.