One of the best first-person shooters ever made for a portable.
The game has a great atmosphere. It has a story that draws you in and keeps you moving forward through all of the action. The controls feel accurate and tight, even given the limitations of the PSP's inputs compared to consoles/PCs. The graphics and sound are sharp, and the dialog is well-written without taking itself too seriously. My biggest criticism of the game is that it is hard to pick up and play in short bursts, mostly because once you've played for five minutes, you won't want to put it down.
Syphon Filter: Dark Mirror may not be the game to play while waiting in line at the bank, but if you're at the doctor's office or on a trip, it can't be beat.