Crush the Castle for iPhone is a simple and fun strategy game. The object of Crush the Castle is to destroy buildings with trebuchets -- a fancy siege engine something like a catapult. You get the chance to be the attacking army and, as a twist, you can even build your own structures and destroy them as well.
The game interface is very easy to get used to. You tap the screen to launch the trebuchet and then again when you want the ammunition to be released. The you watch to see if your ammunition has hit its target. You get to pass the level when all of the occupants of the building have been killed. (Yes, this game is not for the pacifist.)
There are 10 different types of ammo that you get access to as you continue through the game. Boulders don't cause enough destruction for you? Well in later levels you get access to cannons and greek fire (D&D flashback anyone?). There are 90 different encampments. If you get a medal on each encampment you get to progress to the next stage. Once you have unlocked a type of ammunition you can go back and try to use that weapon on previous levels, which makes it much easier to achieve a medal there.
One of the more interesting aspects of the game is that you also get access to the castle editor. This allows you to make your own buildings and then you can find out how easy they are to destroy. It is not the most seamless interface for creating new buildings but after a bit of practice you'll get the hang of it.
This is the perfect game for the casual gamer who wants to have something to do when they have a few minutes to kill. If you enjoyed playing Angry Birds than this is a another game you will like.