Well, I finished the demo and now want more. Building the tower just takes a bit more time and try to build a decent, solid structure for most of it. Once you near the top you can sorta go all stringy. Once the pipe activates its a vacuum that will help support the structure, so get there and you're good.
I have to say, that last mission of chapter 1 was awesome.
[spoiler]Having to climb up and out of the pit. Despite the sign saying you might have to leave some behind, I was able to get all of them out of there.
Then, silly me, I tried to build a tower into the sky...which lead nowhere. My first tower half-collapsed on me but luckily got jammed. So then I built it AGAIN, reaching the very top and being unable to go further. Only then did I realize what those eyes were for.[/spoiler]
So awesome. I have to buy it.