Machinarium - Is it worth $20?

I just saw the game Machinarium on Steam's home page and downloaded the demo, http://store.steampowered.com/app/40709/. It's a 3 level demo and is 10% of the whole game. I liked the art style and found the demo to be somewhat fun, but the demo is really short and at $20 the full game seems a little expensive especially considering other independent games sell for $10 and have about the same total game length.

Has anyone played the full version of the game and can vouch that it's worth the $20?