Quote Originally Posted by Poofta!
these were jap mega drive but the cart was like twice as big
Japanese 32X games are the same size and shape as US 32X games. Japanese Megadrive games are slightly wider than Genesis games. The only carts that were any larger than normal carts were Virtua Racing, and just about any game made by EA or Accolade. AFAIK only EA published games in Japan, though they did use those larger carts (with pink and green tabs in addition to yellow).

I'm curious now -- got any pics, perchance?