Instead of top-down Diablo-like play (which the D&D setting is absolutely crying out for), Dark Alliance was a third-person co-op action game set in Icewind Dale, and starring the Forgotten Realms ...
Instead of the top-down, Diablo-inspired action-RPG mechanics of the previous Dark Alliance games, DA played more like a Gears of War game, thanks to its over-the-shoulder perspective on combat.