Here is my best shot of making a replica of the Gameboy Advance cartridges and turning them into magnets. I even tried to copy their pinout. They should be about the same size as their real counterparts. They have a hole for an 8mmx2mm magnet and should be press-fit; you can always add super glue if you want to be safe. Also, the center cut-out is 43mmx22mm, so feel free to make your own. Here is a link to the ones that I created: https://drive.google.com/file/d/1aBn-v_-XAjh6iC5fBJ8ht07QWW2WOJBE/view?usp=sharing

Let me know if you have any trouble accessing it. Also, feel free to message me if you want to know any of the filament brands/colors I used. No supports are needed. I added a brim to be safe, but it is not needed. If you want the text to stand out more, I recommend a 0.2mm nozzle, but if not, a 0.4mm, which I used, gets the job done.