Okay at for the first few hours.. then problems start glaring.
The game is fun for the first few hours and maybe then some, it's fun purchasing and trying out new guns and abilities, but the story will only last you around 5 hours if that. The problems start when you replay the missions, most of the time spent playing is inside dull buildings, the game is at its best when you're on the streets with zombies roaming around/police lights shining everywhere - the game can look good, it just goes out of its way to stick you in uninspired areas.
It's not a BAD game so much as it's a unpolished/content starved game, which I suppose could be labeled as bad. However there is fun to be had here, but by the time you've finished the game a couple times there won't be much there to keep your interest, I'd recommend renting it.
Also as a side note, would not suggest trying to platinum it, there's a trophy to get which requires you to not just S every mission but S+ on Veteran or Professional which to get a S+ you mustn't die once, which is next to impossible if playing alone because the enemies take a significant amount of damage before they die and do much more to you in the process, the AI are useless on these modes. If you opt to S+ on Veteran you must beat the target time by 5 minutes faster, which is a lot harder than it sounds without dying. Just thought I'd throw that in there.