Good, both online and off!
PSU consists of two main modes, story and online. Online mode is just what it sounds like, you create a character, hop into a lobby, find some friends, then go destroy some mutated creatures. When I played, I experienced no lag and the frame rate stayed pretty steady.
Story mode tells the story of Ethan Waber, member of the Guardians, which is pretty much a mercenary group that works for the government. The story is pretty much not there, so for those hoping for a deep and convoluted story, this game is not for you. Where the game really shines is in its combat. Combat is handled much like an action game a la Dynasty Warriors. The difference is, though, beneath the slicing and dicing, there is a typical role-playing damage percentage counter. So you'll see hp numbers pop up when you slash away, and you'll always want to buy the latest weaponry, because outside of leveling up, the only way to cause more damage is by buying the best, most expensive weapons. There are many different types of weapons from machine guns and light swords to rods and daggers. There is a magic system, called TECHNICs that you can access at any time , provided you've learned the spells. You don't have to be a Force type (a mage type character) to use TECHNICs, but they have the greatest control over them.
Graphics are a mixed bag. On one hand the character models are pretty detailed and nice looking. However, most of the dungeons are quite bland. There is also one glaring problem in that when you're standing still, the piece of ground closest to the camera shakes like an earthquake is happening. This is not game-shattering, but it is an annoyance.
There is the usual upbeat mix of tracks that play in dungeons and towns. It's not awful, but it's not something you'll remember either. The only piece that got on my nerves was the Home Colony theme, simply because you are there a lot.
This game is a very good game, and I would recommend it to anyone who likes action rpgs. If you have online support, you should give it a try, since it's always more fun playing with friends.