Accessories for the unit (much like the SNES) included some game console firsts:
Activator - An octagon shaped unit that allowed a user to interact with games using their body. It
worked by placing the yard wide unit of the ground. The unit used infrared beams between the octagonal sides to detect when you lifted your foot, etc.
There were two games that supported it, Mortal Kombat, and Eternal Champions.
AURA INTERACTOR(thanks Keith S.) - The "first" force feedback device avalible to the generial consumer. It would take the
audio output from a system and then try to filter out the background music from the action sounds and lower the audio frequency to something of an impact and blast it
out the "vest" with a huge speaker. The effect is interesting in some games, unfortunately it usually ends up knocking the wind out of you when you hear the title
screen music, it can't filter out background music very well.
The Menacer (Thanks ZeiraM)- Sega came out in with this unit in retalition to the SNES's new rocket lancher looking zapper.
I believe you could mess around with it and make it a work either like a gun or a miniture rocket lancher. Looked weird.
Nomad- Sega came out with this portable gaget that lets you play Genesis games on a device about as big
as a GameGear. The system has great sound, a 2 player port and an exceptional color screen
The Power Base Convertor - if you remember the old days of Genesis, you know this "emulator". Genesis has a z-80 processor just for this add-on. It emulates Master System games flawlessly and PERFECTLY.