I played through it. One level is ridiculously hard, and I'm not the only one who said so. It has a lot of cool new additions and all that fun stuff. I did encounter a game-breaking bug, but that's to be expected. I reported it. The game is down again, sadly.
Overall, 10/10. I didn't get a chance to try the castle builder or community castles.
Here is my overall opinion on it, a majority of the new weapons are from the Iphone version, including the fire bombs, the purple potion that opens gateways to other dimensions(last weapon), the acid bomb, and the fuse bombs. The ones that were new are the detonation bombs, parachute bombs, electric bomb, and the ice bombs. Of course the real new feature I saw was the different ground levels. Of course when it was first announced on the Armor Blog they also mentioned new weather types as well, but I did not see that in this BETA. Overall it was a definite improvement on the first and the Iphone version. Now all I can do is hope they make an even better Iphone version of this game, if they ever do make one.
Played on a PC for quite a while yesterday. I enjoyed the new weapons and tactics. The Beta version implemented more puzzle solving scenarios than just smashing which was a nice variation (though I love the smashing aspect!). The physics of the trebuchet I thought were improved (more distance /height, etc). In Beta the people vaporize, for some reason I kind of enjoy watching the corpse laying there as I continue demolishing the castle. The new terrain was a nice touch. The series of medals in the previous version was nice as well. In Beta you could only win Gold or nothing.