Elfmania was more a demo than a game: gameplay really suck... And gamedesign too: the characters'moves really look ridiculous, etc...
Megadrive may have had less colours stuff, it's true games. Not only technical demos. I won't say there weren't good games but the greatest technical achievements were well... just technical demos: gameplay really sucked most of the time.
And a lot of games had crappy technical stuff + bad gameplay (compare street fighter 2 on the megadrive vs any (even AGA) versions... no parallax floor, no all musics, no all sound effects, animation not smooth at all, and so on... and real bad gameplay)