In my opinion I don't think its a rip off and if it is you probably don't have a case. I mean I understand you created it from the ground up but there is no proof that they copied your idea. In fact becuse it seems that their idea is more developed with better graphics and such if you take it to court they would probably win. Unless you have solid evidence that you were the first to do it and they literally saw your game on your website and then developed one exactly like it you're not going to have much of a case.