Monetization is ridiculous
Look at games like Egg, Inc. and go for volume over individual purchases. This game will never get a cent from me because they don't know how to properly price mobile games.
Game itself is fine, could use some polishing... certainly no BloonsTD. Doing pvp tournaments and being smart about how you play, you can certainly get everything without paying... but it'll take ages. Lack of maps is disappointing, lack of choosing where I put my towers is disappointing (you have pre selected slots). Lack of targeting options is disappointing.