Great fun, massively engrossing and loads to do.
First thing: You can now buy this game for budget price as 'Sacred Gold'. This includes the 'Plus' pack (extra missions and areas) and the 'Underworld' expansion - a whole new plot to follow which concludes the original story. So if you ARE going to buy it, go and and get 'Sacred Gold' for the full experience. Brand new it's about ten quid. Anyway, onto the game it's self...
I was disappointed to read Gamespot's review, especially the part about the combat being unrewarding - on the contrary, I believe Sacred's combat is very rewarding indeed, especially if you are using ranged weaponry: You never run out of arrows this being an action RPG (just like in Baldur's Gate: Dark Alliance II in fact) and I find little more satisfying in the game than sneaking up on a group of Goblins and unleashing my burning arrows upon them, each one hitting it's target with a satisfying 'Thwump'. It's very easy to fight, you simply hold your mouse button down over a character. If you have 'follow' mode on your character will continue to attack the enemy over which you originally held your button down on, so you don't have to trace the enemies around the screen you can be lining up for the next one. Blood and Gore abound when you kill enemies, critical hits causing them to explode and some kills leave the body on the ground spurting blood in the air like there's no tomorrow. On the whole I find this extremely satisfying!
The levelling system is excellent too. The cap is set to a whopping level 250, but I think the most anyone's ever gotten to (judging by the on line leaderboards) is about 217. At first you level up thick and fast, I got to level 5 in about and hour. In combat, a cool little feature is that every time you strike an opponent the hit point damage you've done floats up above their head for a second so you can judge how well the fight is going. Also, when you kill things the experience points you get do the same thing. Quests and subquests reward you with much experience too, and then there are Oblivion-style freeform quests - in other words, there are random magical items and secret weapons and very strong opponents that you will occasionally happen across by accident with no quest script associated with them - just cool secrets that you can spend hours and hours looking for yourself.
Making money is ridiculously easy in this game too, although some items cost tens of thousand of gold pieces so it's no hardship ;). Nearly every creature you kill will leave some kind of weapon behind, with great names such as 'Short Bow of Oblivion' or 'Helm of Cinders'. Because of the limitations of your character (different characters can only use certain armour that's designed for their race) you are never short of things to sell, as the game will still throw items at you that you cannot use at all.
Wandering the wonderfully looking countryside (with all manner of environments from open planes to snow covered plateaus) and finding loads of stuff to kill and freeform quests to happen upon is a great experience. And the best part of this? You can play the entire game, quests and all, on line with a mate. Oh yes indeedy. The monsters are levelled up per the number of players you have going so as to keep things well balanced, and characters are saved straight to the server so there's no need to worry about overwriting your single player game, the two are kept entirely separate.
All in all, Sacred has great graphics, great and intuitive gameplay, lots and lots to do, it's all co-op if you want it to be, the only let down is the sound... Sparse music and too-quiet amateur sounding voice-overs (inspired by the Monty Python films by the sounds of them) let it down somewhat, but the atmosphere isn't spoiled too much... As you'll see when you obliterate an army of Orcs, with a Halberd of Flames, in a forest ,as the fog rolls in, blood everywhere, your character scream 'Vae Victis!' (or something similar at least. Sorry about that, Kane :D )