Was just coming to post how incredible some of the level design is. I'm struggling with 2-5 right now which is just insane.
I finally unlocked VOLCANO weapon....MWAHAHAHHAHAHAHA
What I didn't know and I like a lot is that generally (me anyway) you play a level till you star it (1,2 or fully 3 star) then you go on.
Then you hit a 'wall' or your weapons are inadequate for the task (the game warns you), so you go back, and try hard to 3 star it or, even better, to get the top score achievement, which is the hardest but grants you a big leap in the progression bar.
And the levels feel totally different so, you find new routes, you activate switches you didn't care before to or try all the best places for combos.
In this, stages length really help...you will die a lot but levels are relatively fast.
And then you unlock a new power or weapon....and levels that seemed impossibile minutes ago now are manageable (there is nothing easy in this game).
At first I thought the dev said the game is hardcore because in the very beginning I thought it was really hard.
LOL....I knew nothing....
The levels with ice or wooden structures are insane.