The levels after 10600 are really annoying, although I have completed 45 levels this week. The first episode is really unpleasant. Compared to the other episodes, the second episode is more acceptable.
I have completed the fourth episode. Compared with the previous three episodes, it is really much better. 10428 requires more effort, but overall, the fourth episode is both interesting and ingenious.
I finally finished the first episode. It was too torturous and totally no fun. I played 10374, 10375, and 10381 dozens of times before passing it. I was really tired.