So I opened it up. I walked around, did squats, jumped, then I pressed f and built some walls, ramps, and floors with 1,2,3.
I liked:
Very beautiful background.
Smooth movements from the dude.
The Building system works okay.
Could improve:
Not sure how to use the host/connect options.
The Gun didn't work.
There didn't seem to be any gameplay implemented other than the building aspect... I see from the pictures that there are some PvP battles... probably something to do with the host/connect buttons.
I couldn't leave the concrete block.
The building tool only lets you build on the first level... no ability to build up.