I am going to TRY to talk about my first ever game cartridge. My first ever game cartridge was a pokemon gold cartridge for the gameboy colour:
I got it when i was 4 or 5 by my relative. It came with a gameboy colour which was grey, but the battery leaked badly so i had to throw it away a few years ago. Here is what it looked like (the same model, i think from the internet):
It was actually pretty cool for the small fetus that i was to actually hold a screen at that time, it most likely have sparked my love for nintendo handhelds.
(PS:I never did get to go out of the first town because I was a really smart kid and i was 4)