[M1911Colt]

Originally Posted by Smiling Spectre

Seems like clear Diablo-clone for me.

So I can guess Darkstone, Nightstone (variety, huh?), Throne of Darkness, Prince of Qin, Sacred and maybe Akuma.

That is the right track visually, but I don't think it was open world or had an inventory. It just dropped you in to a castle or dungeon thing and told you to go to the exit. It also may have had puzzles in it but I don't remember any.