Having now played the demo, I reccomend others to try it as well. It is a fairly large demo world set up and looks nice.
The major change I'd hope to see though is a running option. Maybe toggle it with Select or an on screen button for easy on/off use. Traversing maps can be boring and is why I ultimately left the demo.
The actual building/destroying works well, the movement does also. Despite my efforts I couldn't walk off of any maps or glitch anything easily, so everything seems clean there.
Any other impressions?