One other thing is the way the game handles missions. But in Cantata, they happen on very large maps, and drive you through a bunch of objectives. Each of them can be like an RTS campaign in miniature, from humble beginnings and scouting to super-unit driven assaults on the ultimate base. You'll unlock the entire tech tree during each mission, and I don't know if that doesn't play against longevity of the game, especially when the combat system is fairly simple.
