I liked it. It was super short, and the interface was "streamlined", with elements that you'd expect from an adventure game looking toward a tablet interface, and more than a few bugs. It looks like a tech demo, a true vertical-slice, with some areas more polished than others.
In general, the level of polish was quite inconsistent, varying from "oops, that was odd" to "WOW... that's basically finalized!". For example, all the custom fonts were in place, backgrounds looked pretty final with proper anti-aliasing, but some of the environment effects and animation triggers need work. The animations themselves are very nice; their animation team are definitely pros.
The opening animatic was great, and the sound-design is coming together nicely. Unfortunately, their development schedule has voices coming in near the end of production, so there are none (perhaps due to the Two Guys roots in triple-A development, where voices are recorded last?). Maybe it's a Linux demo bug, haha!
It is missing a TON of the writing, and there is lots of placeholder text, aside from it being very short (perhaps shorter than this forum post), so it's a bit difficult to evaluate exactly what the final product is going to be like. However, from what was there, the tone of Scott's writing is definitely present, the music sounds like Ken Allen at his best, and the player-controllable Rooter character adds a "buddy adventure" mechanic which is really cool.
Beyond that, I can't really give you any semblance of objectivity. I have a double dose of subjective distortion on that project. First, I'm such a horrible SQ fanboy, I had a hard time not giggling with glee while the demo was still downloading, and leaving it up and running in the title screen to hear the music a few times over. Second, I backed that project past the point of confirmation bias, so through the lens of my pledge it's easy for me to dismiss flaws that others may have a problem with.
I think it's going to be an awesome and funny game, and that you should go to guysfromandromeda.com/store/ and give the Two Guys your $15 pre-order, not so much because my opinion should be trusted, but because doing so will make me happy. Then I will say "thank you, rugged!". I know that your pre-order money will go toward making the game better.