One of the hardest games I've played in my life, but a staisfying one.
Killzone Liberation has one of the better production values for a PSP title, including addictive gameplay, cool graphics and fantastic sound. The single-player campaign may be regarded as short, but it can be stretched for a dozen hours more considering the nut-cracking difficulty. The challenge games make a nice distraction from the main campaign via super short but engrossing bonus missions which earns you a string of medals that look good onscreen. Killzone Liberation is a classic for the PSP and its deep (albeit frustrating) challenge makes it a pretty
good game to pick up any time.
KingLim