I have it. Beat it. It's currently collecting dust on the shelf.
It's close enough to Diablo II to be concidered a knockoff.
The graphics are ok. The vice acting and cinimas are weak. The storyline is very "meh" and only has a minor connection to the OVA and TV series. You don't have "classes" or anything because there is only one playable character. The gamepay is good once you learn the system. The game can be cheap at times and some of the bosses and sub-bosses can be pure cheese (the dragons, the big sand worms, the big mithril golems, the paddle queen... I could go on).
Instead of a skill tree, you have the "rune" system. In the inital level you find a starter set of: sword, shield, armor, boots and helmet. Over time you'll hook up with a dwarven blacksmith who can upgrade your gear. He can do it in one of two ways: 1) when you find new gear, he can transform your current gear into the new gear while keeping your rune upgrades (it souds weird at first but it's kinda similar to the Secret of Mana weapon sphere system) 2)all over the island there are rune "words' written on stone monuments. Once you can read them, the blacksmith can write them into your gear to power it up.
Furthermore, there are two different kinds of rune: 1) ones that give a permanet stat increase 2) ones that must be equiped which give an effect, like life stealing for the sword or walk silently for the boots.
In this game, exp and level dosen't mean jack. You live or die based on how you set up your rune upgrades.
Compared to Diablo II the world is bigger and much more varied. Which is both a blessing and a curse. There's a lot to see and change is good but it's easy to get lost and getting around is a pain in the ass (especially early on, before you have the warp gates unlocked)
The one serious problem with the game is that there is a major treadmill effect after you get past the halfway point. It's a major test of patience to finish because the game is so damm stingy with cash for those oh-so-important rune upgrades.
Try the game and see if you like it. I didn't paticulary care for it because it's such a time sink (which seems to be a common thread for DC RPGs. Tmestalkers and Evolution 1 & 2 were real bad about that, where you had to spend hours and hours to get anywhere. The only DC RPG I honestly enjoyed was Skies of Arcadia). If you liked Diablo or Diablo II you'll probably dig it.