Thankyou to everybody who replied!
At least I now know, the game plays fine and saves fine (for now),
Some great advice and photos here.

The only consulation is that it's at least a good fake!

Hi all, Please could somebody have a glance at these photos and see what you think of them? I've recently started collecting GBA games and this cartridge caught my attention, it's supposed to be a USA version of Mario and Luigi superstar saga. I have no numbers indented on the label, the label looks...