The Sega Mega Drive 688 Attack Sub is a PAL region video game released in 1991 for the Sega Mega Drive platform. Published by SEGA, the game belongs to the War and Action & Adventure genres, with a sub-genre focusing on Navy battles. The game, part of the Sea Attack and Strategy series, features a manual not included and carries an E-Everyone rating. Players can expect an exciting gaming experience as they navigate through various missions and engage in intense naval warfare.