This reminds me of the Nintendo e-Reader. It was a Gameboy Advance accessory that plugged into the game card slot and had a dot code barcode reader. Some cards

This reminds me of the Nintendo e-Reader. It was a Gameboy Advance accessory that plugged into the game card slot and had a dot code barcode reader. Some cards unlocked bonus items, but there were also NES game cards. If you swiped all the cards for a game to load the rom, you could then play the game.