Sprites and maps on a megadrive and Jaguar? Both of those systems are a pixel mashing machine, so for example... This engine won't be able to create the pyrotechnic effects of Tempest 2000, or the flaming haze effects in Sonic 3 / wobbly water in Sonic 2.
For a basic blockart system like that, you'd want a snes. And even this had gradient layers and neat palette effects. Donkey Kong Country for instance, when the light changes from sunlight to nightfall. Still looks bling.
[doublepost=1526336543,1526336010][/doublepost]I've looked at the c libraries for Megadrive, and while it is cool, I came to the conclusion that you're better off making custom bling. Although seriously, a lot of the Sega arcade ports are using generic C, but it seems to have custom hex optimisation. Probably a secret recipe of some sort.
For Dreamcast/PS1 I can imagine you could write some cross-platform code for a 2D engine. For the Megadrive(Genesis) or Jaguar I would think this would be harder.
If it was really easy to have fancy 2D games on the Megadrive they would have already made them, but I wouldn't mind if they prove me wrong.