It's multiplayer is pretty fun but singleplayer needs work...
The graphics are pretty good, especially the environments. There is so much detail in each level in both single and multiplayer and the lighting is beutiful. However, there is an exception in the character models. Some of them look rather ugly up close.
Singleplayer can be fun to play around in but it can be kind of frustrating. First off, you can't save midmission. This can get kind of annoying at times as you have to do it all in one go (the checkpoints still help though). Second, the plot isn't so great. I don't want to spoil anything but I'll just say that the plot could use a little work. Other than that, singleplayer can still be kind of fun.
The best part about this game is its multiplayer. There aren't that many levels to choose from (offline) but the game modes and the given levels are all fun to play with. I like how you can customize your weapon selection and there are plenty to choose from. There are only two vehicles (a hovercraft and a robotic suit thing that can fly) but both are fun so you don't really need anymore. The other thing that I like are the bots. The A.I. is actually pretty good but they don't seem to play capture the flag very well. Other than CTF, the A.I. is quite intelligent.
Perfect Dark Zero is a fun shooter that you don't want to miss, especially you FPS fans. If you are looking for a new shooter, you may want to pick up this one and give it a try, you won't be dissapointed...