When we announced the game in august 2012 we showed more of an idea of the game than the actual game content, a vertical slice if you will. We'd been jamming on lots of different ideas, but as the game came together over the following months lots of stuff was changed to be more fun or more polished, and lots of stuff was just left behind for good.
If you watch the Sogport trailer from January, you'll see something a lot closer to the game than the announce trailer was, but you'll still be able to see lots of differences, things we changed or removed.
Actually, I'm going to do a Reddit AMA with Rex Crowle, the lead creator of Tearaway, in about an hour (5pm gmt) so feel free to come ask him about stuff, he's far more interesting than i am