Disclaimer: I was a PM on Angry Birds.
This is such a great demo. The original used Box2D,LUA scripting, and of course you had to make enemies and levels.
There's obviously no expectation that you'd make a hit game from the tech in its current state. You're bound to be limited by the tech, rather than your own skills.
But for rapid ideas, for prototypes, for game jams, this is a game changer. I can also see it as a great alternative to Scratch for kids to play around with ideas. Hope to see more platforms try to turn this into an offering!