Cu-On-Pa SFC is a Super Nintendo Entertainment System game released in Japan, with an English translation patch by Aeon Genesis. This suggests that the original game was in Japanese, and Aeon Genesis created a fan translation to make it accessible to English-speaking audiences. The nature of the game itself, however, remains unknown without further research into Japanese SNES gaming archives.

Cu-On-Pa SFC (Japan) [En by Aeon Genesis v1.0]

Crayon Shin-chan 2 - Daimaou no Gyakushuu (Japan)