There's the often overlooked "Captain Claw" (sometimes called just "Claw") platformer that Garrett Price designed and Monolith put out around the time they were doing the 3d mecha-robot game "Shogo" (one of the easter-egg items in Shogo was a Captain Claw doll that would drive your opponents insane with its witty retorts).
Claw is obstensively old-school. 2D, baby, with hand-drawn sprites, and a level editor to boot!
It's probably abandonware by now. Last I checked, there was a "Real Arcade" release of it, but I think it's passed into obscurity as well.