The best mod would be changing it from batteries to a cell phone style rechargeable battery. At least then I wouldn't care as much of how quick it dies since im not replacing a ton of batteries every day. Even rechargeable ones, you still gotta take them out and put them back, which is annoying as well.

I miss mine as well. I remember as a kid our grandmother got me and a few cousins it for Xmas one year. I also remember breaking it the following year during a parent kid picnic at school where it got crushed. I still remember it, which says a lot because I have very few memories from way back then!

Edit: of course they made this mod! If I ever find one for cheap I would love to do this just as a hobby.

https://handheldlegend.com/products/cleanjuice-game-gear-rechargeable-battery-module