Playing Tetris on the Genesis the other day I found out it has something called "doubles mode", where both players play co-operatively on the same field at the same time. The field is 12 blocks wide as opposed to 10. It's really nutty and I think it would make a great TAS if someone were up to it. Presumably the goal would be to max out the score, though I haven't checked yet what the max is I just assume it's 999,999. Both players share the same score also.
Wikipedia wrote:Sega also released a Tetris game for the Mega Drive, however the ensuing blitz of litigation ensured that it was hastily withdrawn - possibly before it even reached shop shelves. A handful of copies remain, which now change hands for as much as 800,000 yen ($6600) making it probably the most expensive Tetris game in the world.[/quote]
