It’s a tech demo in terms of length and content. But this tiny thing is a beautifully execyuted side-scrolling shooter, and certainly the closest thing to Rez I’ve seen on the iPhone so far. It’s also a really nice use of the touch screen - sweep a finger over the enemies to target, release to fire - whereas most apps I see are tending to treat the touch as merely a way of faking traditional controls. No! Look at Zelda on the DS for how touch should work. It’s also free. Go play it.