The first Gameboy Advance game I ever owned. Incredibly addicting.
Unfortunately it was stolen from me by my older brother's friend about 18 years ago. It was impossible to find even on ebay when I was in high school -- and now that it's finally being sold online, it turns out that it's as rare as I thought it was. You can't find the game for under $500. Wish I could have at least kept the box, but I've never been a box keeper.
I'd call out the guy who stole it, but it's probably pointless at this point in time. I'll probably never forget though. I remember crying about it and everything.
Only thing I could say I didn't like was how short it was - not that I actually beat the game. I just learned that while I was searching for it in high school.