It's been a while since I've played these kinds of TDs. And quite frankly, these kinds are rare.
I'm liking this game since it's quite challenging but of course, I saw some minor setbacks. The first thing that I noticed was the targeting system. As soon as I encountered flying units, I saw that the targeting system was somewhat.. off. Archers were sort of confused as to which unit they would like to attack. Also, I did not see some sort of target priority. Something like Archers to Flying units, Swordsmen to ground units, Knights to nimble units.
I noticed that some unit waves were a too close of an interval to each other. And that some wave combinations were too imbalanced.. unless of course you had the perfect strategic tower placement. I don't know if you did that on purpose or not but if you did it for challenging players, I really think that you could tone it down.. maybe a little. XD
I did like the unpredictability of wave movement. The way that you design two paths but the waves would just go through one path with the occasional "let's go to the other path coz that path's too mainstream" kind of thing. It was a nice touch.
Overall, it's a nice game. Would look forward to a sequel if there was. It was funny of you to highlight the word "strategically" in the tutorial. :D