1UP - Tropico 4 is more of a giant expansion pack than a true sequel. It features very few new art assets, the music is ripped from the last game, and the core gameplay is almost exactly the same with a few interface tweaks. That said, I have a hard time faulting the game for it. It's a polished version of an already great game with 80-plus hours of content for $40. That sounds pretty good to me.