If you are considering purchasing a game entitled Pokemon Chaos Black, you might want to reconsider. The figure on the front is from a Sonic the Hedgehog game. This game is a "hacked" or "rom" version of the Fire red and Leaf green games.  I recently purchased one and found it wasn't what I thought. The pokemon appear to be all new, until you view their icons in the menu. Then they appear as the pokemon they were created from (ie: Flaon looks like Charizard). Some versions of the game don't allow you to save your progress, and others do but the game only works until you reach mt. moon. If you have already purchased the game, a glance inside it will tell you it's not a licensed Nintendo game. With a real game, if you shine a flashlight into the edge connector (the green *thingie*) inside the card, you should be able to see the word "Nintendo" followed by a serial number. These games do not have either.  If you'd like to find this out for yourself, buy one or just type the name in a search engine. You'll find many gaming forums that discuss this.

My advice to you is to research games online before you buy to make sure you're getting an original game.