Character designs, visuals, graphics are all amazing, though the quality was not the best because of my device, I say it will have better quality depending on the device. Gameplay is smooth, storyline is straight forward, music is ok (I have listened better), and pretty F2P friendly, which are rare. I do play this as a side game that I don't focus to and it's pretty smooth and not that really repetitive. Overall great game for any tower defense game enthusiasts out there. But do use your characters to the full potential to make it kinda F2P friendly.
That's all, not gonna spend to much time.