Along Nintendo Game&Watch retro games http://www.handheldmuseum.com/Casio/ has many low quality pics of old handheld games by Casio (some share CG model numbers similar to Prizm's fx-CG name) - I wouldn't mind trying to port any of them if someone happens to have higher quality sprites and some videos or picture sequences capturing the game play.

I made a similar post on Prizm forum https://www.cemetech.net/forum/viewtopic.php?t=12767 but thought Nintendo and retro game fans will not look there so hoping to get more feedback here.