A standard entry in the "point and click" action rpg genre.
In line with the 4 major classes, are 4 character skills: archery, melee, combat magic, and nature magic. These skills slowly improve the more you use them. Want your characters melee skill to improve - use a melee weapon. While it is possible to develop a character that is well balanced in all 4 skills, there is no benefit in doing so. You end up having a severely underpowered jack of all trades, master of none. It is much better to have a highly specialized character in one class.
Each class also has a sub skill tree associated with it. As you level up in your respective class, you gain skill points that can be assigned. Depending on your preferences, there are many different paths to take. For example, you could make a warrior who specializes in 2 handed weapon attacks, one that specializes in shield defences, or one that dual wields weapons. Again, it genereally benefits your character to pick a specific path and specialize.
Combat is fairly easy. On the default difficulty level - and consequently the only one you can access at the start - you control a party of up to 4 characters. You can only control one character directly at a time, but you can set the AI to have the other companions mirror your actions or simply attack any enemy on screen. To attack an enemy, simply point and click on them. Your character will attack them with whatever weapon or spell is equipped. As your characters progress in levels and subskills, they gain access to certain power skills then can be used. These typically involve very powerful attacks that can be used once, and then have to recharge by attacking more monsters. And that's about it. Point, click, and repeat.
You start in each main area in a town and then journey out from there to progress the story. As you travel around, you will uncover teleporters that let you either warp back to town or teleport to a previously discovered teleporter. This helps to cut down on some of the backtracking that you will be required to do. The first Dungeon Siege was very linear - you never had any incentive to return to town or a prior explored area. The developers have made some changes, added some side quests, and improved upon this shortcoming. Many of the sidequests will have you returning to town or searching out old areas to gain access to previously restricted parts.
The story is mostly underwhelming. It's nothing bad, just nothing that novel and fairly cliche. Stop the evil villain from destroying/enslaving the world and avenge your fallen friend.
Sound wise, the game plays well. The underlying musical scores are done by Jeremy Soule - who many of you may be familiar with - and his haunting scores permeate the game. The only downside is that the music seems to be too much in the background and hard to hear.
Graphic wise the game is decent, but a little dated. It's certainly an upgrade over the prior dungeon siege and other diablo clones, but doesn't offer anything that breathtaking or notable.
All in all, this was a solid and fun action rpg, but nothing spectacular. Not a lot of deep strategy involved in the game - it's a game where you can just jump in and start playing. The first time through it should take a thorough player about 45-60 hours to finish. Once completed, you can unlock higher difficulty levels, but there is not a lot of incentive to replay the game. Diablo fans will likely enjoy this game, but hardcore jrpg fans may not like the lack of an engrossing story.