I'm against continuous work
in principal In practise I can't help myself! Though I am a bit disappointed that the game didn't end up as complete as I wanted within the 7 days. I blame post-operation lack of energy and my computer blowing up one of the days :-/
I've been thinking of different terrain types, yes, as well as different structures for levels and a few more enemy types. I might also remove the ordered nature of the zones, letting the player choose which order to complete them in. I've no idea how balanced that would be though
For melting ice there is Blaze, which does a rather terrific job when combined with Explode or Breath. I might have toned down its power too much in the last update though.
I take absolutely no offence at the "patience comment - indeed, I am rather proud of it. Damn right my games require patience! This ain't no simplistic shooter. I could do with making the game less grindy though, especially early on.
I'm pretty sure the Titan King is quite beatable at present, mind. Try Bombard 2 and Dazzle level 3.