Short but sweet if you ask me. I liked this game, for the PSP it does have quite a bit of class to it. It was quite short, can be completed in a day if you want. But aside from that it is a pretty good game. If you want a game that is full of action this has it but this doesn't have longetivity, it's not a game that's going to last you for months.
So far I've found this game pretty hard to get to grips with on the PSP. I'll admit I'm not the worlds greatest gamer but I found this near on impossible to do even at the normal difficulty level. At easy its slightly more accessible but even so I've not got very far. I'm going to blame it on the complete lack of ammo to pick up but its probably more to do with my untrained little thumbs.
Its a great game in theory, but much more enjoyable on the PS2. In my opinion it hasn't made the transition to handheld that well at all.