A bit difficult at times, but great hack and slash action!
When I hear the words, "It's like Diablo," I definitely get interested. Diablo 2 remains one of my most-played games of all time, and I crave hack-and-slash RPG's in a similar vein. Thankfully, Titan Quest offers up a sizable, fun experience very much "like Diablo."
GRAPHICS
For the most part, Titan Quest is a very pretty game. It doesn't do anything too technically impressive, and its style isn't going to make anyone stand up and sing to the heavens. But overall, it's very solid, I genuinely enjoyed scouring the landscapes, seeing new monster types, and seeing the way different armors looked on my various characters. You'll notice a bit of repetition and palette swaps, but not so much as to be a deal breaker. My only real complaint is that many of the tombs and dungeons look far too similar for their own good. More indoor variety would have definitely gone a long way.
Character models look good, and everything animates fluidly. There are some satisfactory thuds and cracks as the thousands of bodies hit the floor. The music is suitable, if forgettable. The cutscenes, though sparse, look great and add a little bit of flavor.
GAMEPLAY
How much fun you have with Titan Quest is going to relate directly to how much you enjoy hack and slash RPG's like Diablo or Marvel: Ultimate Alliance. If you enjoy seeking out more powerful loot, grinding out a few levels, and annihilating wave after wave of enemy forces, you'll dig the hell out of Titan Quest. There are plenty of quests and side-missions to keep you occupied, and I found many little caverns and small nooks with all the satisfactory treasure a Diablo fan like me could want. However, like most hack and slash RPG's, it can be frustratingly tedious and repetitve beyond measure.
One definite point of frustration for me was the difficulty. For the most part, I blew through enemies without breaking much of a sweat. The mini-bosses and rare random bosses can be appropriately challenging, but still feel fun. it's the major bosses of this game that drove me batshit crazy. Time after time, I found my characters lacking in necessary strength or equipment to even stand for just a few seconds with them. They are eventually beatable, either through leveling or ultra-powerful equipment, but I was gnashing my teeth at the sheer amount of backtracking I had to do in order to become powerful enough to take them on.
OVERALL
Titan Quest is the best Diablo clone to date. If you're like me, and you're looking for something to tide you over until Diablo 3, give this a go. It's a hell of a fun game, it's relatively cheap, and you'll have loads of fun mashing and blasting your way through countless enemies. Just be prepared for some insanely difficult boss battles, the occasional hour of "seen that, been there," and the essential loot/level grind, and you'll do fine.