Pop'N Music Series

Cheat Code Central: Pop'N Music 2
Cheats and hints for the Dreamcast game.
http://www.cheatcc.com/dc/popnm2.html

GameFAQs: Pop'n Music
Includes title and release data, game guides and FAQs, reviews, cheats and hints, and a discussion board for the PlayStation game.
http://www.gamefaqs.com/console/psx/data/575055.html

GameFAQs: Pop'n Music 2
Includes game information, FAQs, game guides, cheats, hints, and a message board for the PlayStation version of the game.
http://www.gamefaqs.com/console/psx/data/575906.html