An Unreal Engine 3-powered top-down shooter by a former programmer / designer of Epic Games. Coming soon to PC (Steam) & iOS in March 2014. Subscribe to the TouchArcade YouTube channel Source: http://www.laserguidedgames.com/ra/press_release.htm.
Raptor was a definite inspiration. I played it so many times as a kid. On touch devices it actually is a little closer to that since with just touch it picks ground/air for you based on what is closest whereas on PC there are two buttons. Of course some weapons are only one or the other so you can prioritize.