You can check the "growing week" tag if you've missed any of the puzzles in the series. Based on ratings, the list goes
Monday - easy start (in fact, my lowest rated puzzle ever)
Tuesday - medium
Wednesday - quite a bit harder
Thursday - about as hard as Wednesday, but gimmicky
Friday - slightly harder than Tuesday but not too much
Saturday - ULTRA HARDCORE. The most challenging puzzle I've made by a long shot, and it's close in rating to this monster, which was MEANT to be unfair
I wonder where this one will end up. I'm guessing around the Tuesday one if not slightly below it.