I bought a game there once and it worked fine. The only hitchis that they want you to use their own library/publishing software or whatever it is called, so you can't use Steam or Origin etc. Don't know how multi player works though as I bought a single player game.
I can reccomend g2a.com though. The prices are really good and you'll get a product key to use on Steam, Origin etc. and it says on the product page what region it works for. They also have a trade system between users which is a little complicated, but it should work fine if you just follow the instructions.