Excellent, but it's not perfect
Very fun game! You certainly had me hooked for about two hours or so.
Nice concept. I was interested in the mix of tower defense and monster combat, but the layout was a bit too avant-garde; it was too much of a headache for me to even think of a strategy to use with all the choices and the lack of information, or rather, how hard it was to get the information.
The art style is incredible. I love the Boss effect on the village, and the kooky style on everything with the simple shapes and black and white silhouettes, coupled with the very atmospheric background and sky.
I love the monsters themselves. Their styling was very creative, but I have a complaint with how generic the Undead branch is and how jarring the evolutions for the Spirit paths are, especially when your Star Wraith is suddenly a melee type.
Speaking of which, I would like more information about the evolutions before its too late. Please give me how each creature plays in their evolution card, so I won't make a decision and immediately regret it. Story wise, I was impressed with their appearances and flavor text, but practically, I need their stats like how they attack and what exactly their special does.
I would also like to recommend some backwards evolving. Though the Comet Special is amazing, I enjoyed my Mirror Image more than that, and especially with Frost Strike that is pretty much useless against bosses, the ones I actually use it against.
The boss system also gets tedious. When you actually are armed and confident that you can take them on, I would like it if I could jump right into the fight instead of having to slog through increasingly repetitive and frankly boring waves to get to the good part: the bosses.
The towers are also pretty strange. I would like more range on them to prevent Ledge Campers (as I've deemed them), and an evolution and devolution path, so I can build one basic tower then upgrade it into the others. There's just too much choice initially that I slogged through the entire thing with just basic towers as I didn't feel like risking on the more specialized towers. If the choice came more gradually, I would have felt like experimenting instead of avoiding the hard work you put in.
Some more story would be lovely. The game obviously tells a story in the beginning, but I would love it if the story is continued during gameplay with characters like the King's men and the Village Elders talking to one another, making humorous banter and quips i.e. "I have a dragon. Your argument is now invalid."
So, all in all, the initial growth into a powerful monster is very interesting and fun, but unfortunately it quickly drops when you cap the evolution tree. I just ran out of novelty, and everything quickly became boring, even with the new enemies that frankly seemed boring, and had way too uninteresting special skills.
In short:
+Great Art
+Fun Beginning
+Interesting Mechanics
+Awesome Monsters
+Very Atmospheric
-Repetitive and boring after Final Evolution
-Too much initial choice in towers
-Story is thrown away after first few waves
-Boss unlock is terrible after you become powerful
-Needs more music tracks