By the same team that brought you Fish Dude, Taikyoku Renju (対局連珠) is a Game Boy port of Renju. Not a lot to say here. Despite not being released outside Japan, the game has an option to play completely in English.
Present at $8C in the ROM:
1989 SALIO & ANex
At the title screen, hold Left + B for about 10 seconds. Unlike Fish Dude, the sound test does not have names for the songs.
At the title screen, hold Right + B for about 10 seconds. Most of the staff listed in this game also worked on Fish Dude.