Up to four players can venture together, and it's highly recommended that you try this out because of how chaotic and addictive it can be, especially with a mix of character classes at a moderately high level and good equipment.
IGN

---------- Post added 19-10-2009 at 10:30 PM ----------

After you're finished with one playthrough ... The game lets you start over using the same character, bringing along all your experience, skill setups, items, unlocked inventory space -- everything but your quest progress.
2x

---------- Post added 19-10-2009 at 10:36 PM ----------

you'll come up against absolutely monstrous bosses, from a fire-spitting flying behemoth to a titanic lumbering quadruped
3 x

---------- Post added 19-10-2009 at 10:37 PM ----------

someone shoot me please