Recently floods of fake Gameboy advance games are appearing all over ebay. This is mainly occuring with the popular Pokémon games.

  <-- Fake pokemon games have black casing and a cheap sticker with a crap battery (After a month you wont be able to save - in my case i wasnt able to save after 1 hour of use) The original games have nice colours; milky green/red, seethrough blue/red or green and maybe some other colours which you can tell are 100% authentic because scammers wouldnt go through all that trouble  to make it look that real. I hope this helps someone as i've been scammed before and I know money's hard to get!!

- if it's sold with the box flattened (they say it will save postage) then it's definately fake) no normal person selling a gba game would do that either.