400msp for a game like this is a steal, honestly. But if you're still sitting there thinking about it, even though its only 400msp, then its probably because its either not your usual type of game, or you may be worried about the content (this isn't directed specifically at the op, but anyone reading this thread).
DR2 Case Zero is not my usual type of game. I think a third person hack-n-slash can find its way into any type of gamers' collection, but there are further elements to this game that set it on its own level. You are given free dominion over Still Creek, but you have a certain amount of objectives that need to be completed before a time limit. Indeed, there is a time factor. Time limits in a video game are always very frustrating imo; if you are in the same camp, you have been warned. The time restriction actually forced me to play through the game several times over a series of different save files. I think, in the end, I may have spent around 10 hours on the game, not having fun slaughtering zombies the whole time, but trying to squeeze tasks into a small amount of time. I suck, I know, but this isn't my usual type of game.
For those reading this who may be concerned about the long list of warnings accompanying the ESRB rating, there's really not much to be concerned about, tbh. I would give it: Mild Language, Blood and Gore, Use of Alcohol, and Intense Violence. Yes, the violence is heavy, but c'mon, its zombies, and the blood and gore is over the top.
Slaughtering zombies with a chainsaw, a spiked bat, and the broad sword is epic fun. There are plenty of things to do, and the achievements are certainly attainable. 400 msp is a reasonable price for this arcade title, and I certainly do not regret my purchase. The only thing I would say is that if you are concerned about the time element, you may want to reconsider; I know I will probably not be purchasing other titles in the DR series because of that factor.
100%: Call of Duty 2 - Battlefield 1943 - Madden NFL Arcade - Civil War: A Nation Divided - The Lord of the Rings Conquest - Alan Wake - Harm's Way - Dead Rising 2: Case Zero - Battlefield: Bad Company 2 - Limbo - Medal of Honor - Carcassonne