I tried those kind of controls on the iPhone once...i don't like them. I mean...it's the best you can do for a touch screen based device and it's impressive and all, but it still sucks. I'm constantly fighting the controls instead of fighting the enemies. As you can see in the second video, the cross-hair locks onto enemies if you come close. Simply because otherwise, you wouldn't be able to hit anything. In addition, these controls work only for relatively slow paced games. It's impossible to play a fast paced game that way IMHO...and Robombs' gameplay is based on speed.
For first and third person games, there's only one way to own: Mouse and keyboard! Virtual joysticks and game pads are just not made for this task IMHO. But that's just me...millions of people are playing GTA 4 with a game pad...something that i consider to be impossible or at least very very painful.