To say a game is "like Diablo" is almost always to make an invidious comparison, since few studios are capable of the level of polish that Blizzard brings to its work, and for indie developers, working at much lower budgets, it's hard to do something that quite compares
Rather than imitating Diablo, it's better to do what Depths of Peril does -- build on the tropes of Diablo to create something quite different, and quite interesting in its own right.
