great game
at first i thought it was boring, but as i kept playing i'nticed how addictive it is for me X3
i have played tower atack games, but they all were so bad.
this one i haven't finished yet, and i will keep playing later,
i hope you can add some upgrade to mix toghether the same auras and so increase the aura effects.
a second release of this game, with that feature, and maybe being abled to revive some units on each wave,(maybe with upgrades) will be awesome ^w^