Why wont my mac pick of some of the keystrokes on my gaming keyboard

So today I bought a new Armaggeddon AK-700 keyboard and plugged it into my mac expecting the normal, plug and play. But this just wasn't the case. As I started using it, I realised that the, CNTRL , ALT, WINDOWS, AND SHIFT buttons weren't working. I plugged it into my PC and everything worked, so it obviously has something to do with my iMac.

Please help