This is a straight conversion of the first ever GTA game to appear on Playstation Portable. The first thing to say is that if you haven't yet sampled the neon excess of Vice City, or the mindbending scale of San Andreas, there is absolutely no reason to buy this as you can now easily pick up either of those games at a budget price. If, however, you're a diehard GTA vet looking for the next fix, this may just fit the bill, provided you don't come at it with expectations raised too high.
Surprisingly, this doesn't really feel like a scaled up hand-held game, more a scaled down console game. Everything looks and controls in more or less exactly the way that you expect. The series has always benefited from an amazing core game engine, and fundamentally it's no different here. Yes the compromises are certainly there if you go looking for them - the scale is pretty restricted, the radio stations loop more frequently, the colours are muddier, the effects more basic and the streets less populated, but actually the whole thing stands up pretty well alongside the other games in the series.
Liberty City is less interesting as an environment than Vice City or San Andreas, but it does have a certain mafioso charm. The story and missions are pretty basic, but there are plenty of them and you still get the same tingle of satisfaction as you complete them - the game is pleasantly addictive. The bottom line is, if you haven't played GTA in a while, and are just itching to cruise the streets blowing things up, stealing cars and shooting things in a familiar ironic postmodern setting, then you may just enjoy this.