The PSP online killer app.
Single Player
There are a good amount of missions (14) in the Single Player. Also a neat thing is the Instant Action mode in which you can go back to which ever level you want and play one of these five modes on that level- Hostage Extract, Stealth Extract, Sweep and Clear, Sabotage, and Stealth Sabotage. So if you are not able to access the internet, there is plenty content in Single Player.
Multiplayer.
Like every single PSP game out, this game has your standard Ad-hoc multiplayer mode. Infrastructure however is the part that really stands out on this game. You can go at it to up against 16 people in one game. Also this game is most likely the first portable game to have voice support online. If you have been craving online action for your PSP, then this is a must buy.
Features
This game also features the Cross-talk function with Socom 3 as some PSP games are doing with their PS2 counterparts. By finding and completing tasks on Fire Team Bravo, you unlock special features on Socom 3 and vice versa.
So if you want a good online game for your PSP or just one of the best PSP games out yet... Pick this game up.