This cartridge holder will hold both Gameboy classic and Gameboy Advanced cartridges. Using the customizer you can select the number of cartridge slots you want, the type of cartridge you want to store and if you want to be able to be able to remove the cartridge without removing other holders.
NOTE: The holder gets pretty tall with "Allow Cartridge Removal" and support for Gameboy Classic cartridges
Source on Github
Prints great with PLA.
Infill: 15% (so that the slot top gets even coverage)
Brim: Maybe. I print with a brim to get less warping. It's up to you