Megaman X will always be a timeless classic I totally agree, very easy to get in too and yet will actually take some time to beat. I have never played Earthworm Jim mainly because I've never owned any of the Sega consoles. As for Super Mario Bros 2, that shit killed me as a Kid haha, but I do agree its combination of platforming and minor puzzle solving is something the gamers of today I think will truly appreciate if they're looking for an authentic retro gaming experience.