The only similarities ".hack//Dusk" has with its predecessor ".hack//SIGN" are a few characters with a changed look and the location all the action is taking place, the rest is different like day and night.The character looks are something that I don't really like, they are just too childish for my taste, in fact the whole anime is kinda childish. Since it's mostly directed towards younger audience you can be sure to see the overall "happy-happy-joy-joy" atmosphere from the start til the finish. You can't create a good anime just by adding lots of cuteness, at least that's how I think.

The story and the action both lack many things. Nearly all the fights end with the same attack move and that makes it a little too repetitive. The story...well, it hardly invokes any interest from the watcher besides the last episodes where it got fairly exciting.
Since it has many cute characters and some comedic moments(not that I laughed at them), then what separates it from the rest of the meaningless magical action anime series? Well, it has quite a serious story hidden inside, or at least it tries to have. But trying sometimes isn't enough, that's why the story takes a more serious turn only in the last episodes.
"The World" being the only place where the main characters can meet each other and the separation factor in the real life adds a little more deeper meaning to the anime but it's kinda countered by some hits to incest between them.

The animation itself is bright and clean with nice CG special effects but the sound quality is something to wish for. Not only is that constant "Renaaaaaaaaaa!!" and "Oni-saaaaaaaaaan!!" screaming annoying but the background music is a failure, it's unoriginal and lacks the distinction.

This anime is clearly meant for younger audience, so happy end is guaranteed. Others who want a more melancholy anime from the same class should stick with ".hack//SIGN" if you haven't seen it yet.