This is a prototype version of Frogger for the Sega Game Gear. Prototypes are early, unfinished versions of games and are usually not publicly released.  They offer a glimpse into the development process, often revealing different graphical styles, altered gameplay mechanics or cut content compared to the final version.   Information regarding specifics of the Frogger prototype is likely limited to those who had access to it during Sega's development stages.

Frogger (USA) (Proto)

Fray - Shugyou Hen (Japan)