It would be interesting if both the level editor and the generator could optionally enforce NES limits. Those limits heavily influenced the design of the games themselves and the levels.
For example the generator just made a level with 5 goobas 2 helmut guys, and 2 turtles blocked by 2 piranha plants. It’s unlikely an NES game could do that and (a) not slow down a bunch and (b) it would flicker like made given it’s 8 sprite limit per scan line. A sprite on NES being 8x8 pixels means most enemies are 2x2 sprites so if you want no flicker you can never have more than 3 enemies in a horizontal area of the level on screen at the same time since once Mario enters that area he’s 2x2 to 2x4 sprites.
A good designer like Miyamoto would generally not have allowed the slowdown or the flicker and so would have designed around it. If the editor could warn you when you’re breaking those rules it would be really interesting feedback for new game designers
