The Mac App Store is pretty decent, in that it offers one-click installs, tracks updates and maintains purchases and so on (like Steam in that way), but doesn't have any requirement to be logged in or online or anything else to play your games.
I am also glad to see that he cut the price to match across platforms.
It's the best one from Soldak, imo. Even better than Din's Curse which is more like Diablo than this one.
The thing I absolutely love about this game are the covenants (The AI you're playing against). You can make alliances, raid, go to war, trade, etc. It turned it from being a typical Diablo clone to something new.