A lot of erotic games, particularly strategy titles, have difficulty balancing the porn with the gameplay. Make the gameplay too complicated, and the game is boring. If the gameplay is nonexistent, however, there's no substance to keep the player interested.
This game balances that line perfectly. There's a strategy element there that you can pay attention to, but at the same time, if you want to ignore it entirely and focus on the porn scenes, which are excellently illustrated by Balsamique, you can. This game rules. Plus, if you're a fan of Dune, there are plenty of references and tidbits here to reward those with knowledge of the franchise.