Originally Posted by
Assman
No, it doesn't really work the other way around. The SMS and Game Gear hardware are practically identical, to my knowledge, but the GG master palette is way bigger (something like 4,096 colors versus 64), so an SMS game will display with no problem on a GG, but if you try to do the reverse, you'll get color values that the hardware can't display properly. This is also why there was never a "Super Game Gear" for the Genesis (the Genesis master palette is only 512 colors, so you'd need a separate video output on the device).
After that, you also have the problem of the start button, which functions completely different from the SMS pause button, and the difference in resolution, which would generally end with excess graphical garbage that was meant to be obscured by the GG's smaller viewing area. There are actually some people out there who have hacked a number of GG-exclusive games to get them fully playable on SMS/Genesis -- excess graphical garbage and all --though, so not all hope is lost.