I've been an avid fan of console action-rpgs for a while now ever since Phantasy Star Online hit the Gamecube several years back, so I have a pretty good reference when rating Dungeon Siege: Throne of Agony (ToA). This review is mostly for gameplay since I tend to not mind graphics and audio so much.
First off, let me emphasize that ToA is a traditional hach'n'slash game. Its greatest appeal will be towards gamers who enjoy mindlessly destroying hordes of baddies, level grind, and item micromanagement. It's most similar to Baldur's Gate on consoles, Diablo on computers, and Untold Legends on the portable front.
Like the afformentioned games, ToA has players select thier avatars--the warrior, mage, and archer archetypes--in the beginning. The three characters already have names, and players can neither customize their avatar's physical featurs such as hair and height nor their initial parameters (stamina, power, intelligence, etc.). This lack of customization is really superficial though; equiping new items will drastically change an avatar's appearance and players can still customize parameters upon leveling up. Also, depending on which character you choose, you can select one pet/follower ranging from a fire elemental to a baby dragon that will fight and level up right beside your character, and many more choices become available as the game progresses.
Characters aren't limited to one class either. Once your avatar reaches a certain level, you may choose one of two hero classes, and at even higher levels, you may choose one of four legendary classes. For example, Allister starts out as a Battle Mage, but he may become a Vile Wizard or White Wizard. Later on, depending on which hero class you choose, Allister may become a Lich, Death Knight, Archmage, or Arcane Champion; each class has unique skills unavailable to other classes.
Deciding on which parameters to level up isn't as much of a painstaking choice either; for example, the stamina parameter not only raises hit points (how much damage an avatar can take) and hit point regeneration, but mana regeneration as well (which helps in deciding how often a character can use skills and magic). Likewise, the power parameter not only raises strength (decides melee damage) and carrying capacity, but a bit of defense as well. Because of this, characters have greater flexibility in how they are raised; a mage doesn't always have to be a spellcaster and a warrior doesn't always have to be a frontliner. This is reflected in the character class progression--in Allister's case, even though he starts off as a spellcaster, the Death Knight and Arcane Champion are geared towards melee
As far as the adventure goes, you're basically relegated to fetch and extermination quests with a few variations thrown in. You press the x button to use your weapon and a combination of buttons to use your magic. The game is very linear making progress a matter of how fast your avatar can kill the enemies--don't expect a God of War action game here. The option of going through the story with a friend does make the game more enjoyable. Even without a friend, ToA is quite easy except for those unexpected mob rushes and high level grunts. That ease is further exaggerated since gold and rare items are easy finds. However, for someone like myself, this makes it appear that you're actually accomplishing something. In the aforementioned Phantasy Star Online, you might have to spend days or weeks searching for the high end rares--something that really irritated me after failure after failure.
User interface is also very friendly. ToA minimizes the arduousness of opening and cycling through the menu. Instead, you can access all of your consumable items, the map, and equipped weapons using the d-pad; Any item drops can be viewed and compared with your current items without having to pick them up; there is no camera control, but rarely do in-game structures obstruct your view. In effect, the game continuously flows except for when you need to equip and re-equip weapons and armors.
The biggest letdown in ToA is probably the loading times. It takes about 30 seconds to enter an area, which really dampens gameplay. The overworld map itself also takes 10+ seconds to load. Even in the main menu, going from screen to screen isn't instantaneous, and this is all happening on a PSP Lite/2000 so load times are probably even longer and unbearable on the old PSP. Also, the developers have decided to my extreme chagrin that you can't trade items between characters. If your warrior finds a powerful wand, you won't be able to give it to your mage. Even in multiplayer mode you can't drop items so that your friend can take it. There are also some glitches where the game may freeze or become otherwise unplayable; make sure you save often so you can restart when a bug rears it ugly head!!! One last complaint, although minor, is that teleporting from a dungeon and back will take you back to the last entrance you entered instead of where you teleported from.
If it weren't for the loading times, bugs, and inability to trade items, I would have given the game a 5. ToA is still more than playable however. Loading times are a drag, but it doesn't hinder combat; glitches can be overcome if you have multiple save files and if you save often. Leveling up, learning new skills, finding rare items, and questing with a friend is just as addictive as ever if not familiar. ToA provides a quality, full scale action-rpg in portable form--highly recommended.