Sega's attempt to crush the Game Boy. Releasing on April 26th (15th in NY/LA), 1991 in the USA, it achieved moderate success but failed to make a significant dent in Nintendo's dominance. This was despite it's pretty powerful specifications, containing a Zilog Z80 clocked at 3.57 MHz, a 160×144 screen with a 4096-color palette, and 24KB RAM. Of course, like with other portables of this era, it's poor battery life of only a few hours resulted in it's failure to overtake anyone but other less capable competitors, such as Atari.

This is just a program imitating the appearance of Windows 98, but it has some function.

https://www.smspower.org/Homebrew/WindowsForTheGG-GG

https://www.planetemu.net/rom/sega-game-gear-public-domain/windows-for-gg-by-victor-kemp-pd

For general information, see the Game Console Revisions Overview.

I need finishing

There are HEHEHEHE versions of this console, arranged chronologically.