Ah, a new one! It's been awhile. So lets get a going.
Parts.
Definately a worthwhile set for the parts, if you are at all interested in the skeleton theme. With three skeletons, three skeleton horses, two dudes, and a horse it's certainally worth the buck. The big wheels that come with are also unique and possibly cool. I know I already used them once. Nothing much else to write home about for parts, but certainally it's decent in that area.
Design.
I'm a little more hesitant on the design. This isn't the first prison carriage Lego has made, and the whole concept behind it is a bit silly. Still, the designers of this set did good and stayed well within the look they were giving the whole skeleton theme. The method used to hitch the undead horses to the wagon is a different design, and I'm still uncertain how well it works, but it's at least fairly stable, a problem that other wagons have had. I don't remember correctly, but I think the prison the comes off the cart? That's both kind of useless and annoying. A point in favor of it though, NO catapult. It would only be too easy for Lego to have added one of those small "pot" catapults up on the tower.
Playablity.
On the note of the removable prison, the playabilty is somewhere in the middle. It has a decent ratio of bad guy to good guy, and the knight having a horse is a very good idea, as it will allow the youngster playing with it to be able to have his knight keep up with the wagon. As I said, the detachable prison is iffy idea. On the one hand, having it detach is an obvious attempt by Lego to add more playabilty to it, and it may work. A kid could indeed have a bit of fun with removing it. The said kid could also have not so much fun with it, as it makes the whole wagon a little less stable, and more prone to loosing its cargo in mid-flight. I guess it depends on the kid and what he thinks make the game better.
So all in all, a worthy buy if you did. And even something worth getting second hand. Good piece selection, moderately good desgin, and fairly decent playability. (Ain't vague grading systems great?)
Dan

I build, therefore I am.
Brave words coming from a guy called grapenuts.