I haven't had an enormous amount of experience with this yet, and despite finishing the original Protector, I see many additions that widen and deepen the scope of the previous, rather simple, gameplay. I now find myself thinking about placing towers far more strategically than I did in the last game - one of the more obvious features that encourages this is that towers now need to be levelled up to have elemental specialties, stopping me from just spamming, say, Energy Magi on a whim when I'm facing a foe weak to energy.
Nice game, this.
Concept is great, and there were a few moments when I was somewhat surprised with the ability of the AI (which, to be honest, wasn't nearly as aggressive as it should've been until level 12). Wasn't immensely difficult overall (I like hard games), but as I said, the concept stands... really very good.
 "Protector: Reclaiming the Throne"){kind=icon}
 "Nano War"){kind=icon}