well so far it is like diablo 1.5 in space.
it has some neat gimmicks and the animations are well done.
id have to play the gladiator and the "sorceress" type character before passing any final judgement on longevity.
no skill trees. each race has unique abilities. humans can lay mines. the others? who knows?
its a good game. the only thing that may hurt it depth is because it has a quarter the staff of diablo 2 if that.
my guess is diablo 1.5 depth of gameplay with higher res (10x7 playable) and less blurry graphics in a giant space ship sci fi setting.
some neat innovations to the genre:
stashes - basically interconnected bank boxes strewn about the landscape. put stuff into one at this location and access it at any of the other locations. item ATM's i guess.
"wells" - not only replenish health but give permanent stat increases
environment interaction - think smaller versions of diablo's seals but much more frequent
mine laying - like assasin traps with no range attacks, so far. spider mines are quite visceral