Somebody – I forget who – noted that Leviathan’s major strength was getting back to the creepy Lovecraftian insidious corruption feel of the major villains, and that’s true. The combat is there, but it’s not a violence-heavy scenario. It’s a couple of good hours of let’s-unnerve-people-a-little, though. Spooky, in other words; worth the ten bucks, and you get some nice War Assets out of it, too. You can pick it up without dishonor.
Plus, there’s the… well, you’ll know it when you see it. And you’ll keep activating it, too, because it’s kind of fascinating.