This flash cart does everything as advertised. GBA games run flawlessly as if you had the original cartridges, real time clock works for pokemon and the other games that use it. The only complaint that I have is that the neo geo pocket/color emulator doesn't really work. The games boot and run, but it's slower than real time, so they're not really playable. Original gameboy/color games run pretty well with the emulators, same with NES. Overall I'd say this is the best upgrade for your GBA because it let's you play all the titles you want, without having to hunt down and pay high prices for original carts that are 15-30 years old.