It took quite a while on my machine to load. The green rotating block on the right shows the loading progress. If you don't see that, chances are that WebGL is disabled or not supported.
I thought that green block filling up was a really nice playful touch. Letting us get closer to the game during a loading screen with an in game element gave me some positive anticipation for when the load would finish.
The green block filling up is all I ever got. It consistently stalls at about 50% for me.
:(
What browser/OS?
Chrome 27.0.1453.93 on OS X 10.8.3.
That's quite weird. It would be really awesome if you could open your developer console when this happens (cmd + alt + j) and then copy what it says and send it to bugs@skycraft.io :)