Here are videos of the two playable levels in the demo. The demo may be removed once the game is released, so play while you can!
As an overview of what I said in the videos, this demo feels like the first four LEGO games, which I consider to be the "true" LEGO games. LEGO Indiana Jones II and LEGO Harry Potter were glitchy, unorganized, and didn't feel like they were made as good as the first four. LEGO Star Wars III uses the new splitscreen "ability" so to speak, and isn't any better but isn't any worse. The overall design of the level feels a lot more like the first two LEGO games, with constant puzzles and refrences from the animated series. I'm also glad they brought back the 10-minikits-a-level that hasn't been the same since LEGO Batman.
Even though this is a demo, I like it more than LEGO Indiana Jones II or LEGO Harry Potter, and even more than the Harry Potter demo. The overall feel, design, looks, and the way the characters work bring back memories of when I made my first ever guide, LEGO Star Wars. I also plan on making a guide of this game, and hope it lives up to the first two LEGO games.