This arrived in very good time to the UK (within 10 days of order) and so far has played amazingly on my GBA SP. If this is from the most recent translation of the ROM then I don't foresee any issues. Game looks great, plays great, saves fine.
Cartridge and label look like a legit game, I'm extremely impressed by the quality of the order, including the case.
To focus on the game; if you liked the first one then you'll love this one. Always liked the Rocket deck as a kid and this game adds these cards, plus many more with an additional area to explore. More of the same, and then some.