Boy is it unforgiving! I feel like most tower defense games don't make you build your defenses in real time... and the timer isn't very long.
I love the graphics, and I love all the customization options! Once I got the hang of it, there was a fun groove!
Currently, it feels like there isn't much progression built in... you start with all the build options unlocked, and there's no way to increase how quickly you generate wood/steel/gunpowder, so there's no reason not to pick the best stuff available.
The dragon enemies are mean... none of the weapons I tried were able to stop them before they torched my entire base.
I love the little sound effects used, and the simplistic style really works for this type of game!