Nice graphics! Somehow it reminded me of Bleach. I got victimized by the disappearing platform in the ice stage too. Also, in one of the ice areas, if you fall down the cliff and the ice columns crumble and crush you... everything else crumbles and you fall in an infinite drop, unless you choose "Quit" from the Menu!
This is one of my favorite TD's. It didn't get boring or insanely difficult in advanced levels. "Player" level up and skill distribution elements are a nice feature.