"Powered by Unreal Technology." It's a big selling point for any app these days. But some developers seem to forget that just because you use one of the most advanced graphics engines on the iPhone doesn't mean you can forget to, you know, make an actual game. PD -prope discoverer- (yes, that's the name, and every time I mention it in this review, you'll have to read this) is a decent-looking demo for constructing an environment, but there's nothing else there.