The sound thing is a somewhat big deal. What would really be awesome is open feint, game center and in app purchases. I know that this is a start up but these features are essential. If you guys did this you would be the only visual programming engine to do it. You would be ahead of game salad and game maker.
If you guys implemented these people would flock to the engine. The only other engine that you can use is the Corona SDK. But coding in lua is somewhat annoying.