And you should add some sort of endless mode. Perhaps getting the color bars leveled up in this mode would give you a temporary special effect or spell that you could cast.
Simple suggestion: When you earn a new Talent, it should glow slightly or stand out in some way the first time you visit the 'Skill' page after being awarded it. It is a pain to mouse over all the different talents to find the one you were just awarded and see what it does.
I never knew how negative I was with all my comments until I played this game. I feel like this game really taught me something about myself, and for that, I say thank you. Game 1/5, thank you, and no, I won't give you a 1/5 rating. You will get the 2/5 you've earned (there was no mute button and the graphics were pretty terrible...)!
Tower targeting is weird. The towers seem to target the creep furthest away from them, not the creep furthest down the path. There's no way to speed up the game or quality options either.