Interesting little game! I tend to agree with you that level design will always take longer than you expect. :) But, overall, I actually didn't have any major complaints! It was a bit small - make sure you have your stretch settings setup in the project settings to keep 2D canvas items, and make sure when you post the project that you make the screen a bit bigger (just easier on users, I feel). Pretty good game though! Didn't get very far because I couldn't figure out how to get more stuff to move the wall, but I still enjoyed it.