Here my replays, I skimmed through the pack in the last 24 hours or so, was very fun and sometimes frustrating!
A rough difficulty tier list for me personally, based on how long (or how many fresh retries after doing other things) I needed for a level:
Simple:
Solitary Confinement, Frog Fractions, Diodes, At the Pond, Overhead, Scraping the Scripture, Centipede, Ifo Island, Spin Me Around, African Wigwam
Medium:
Dadly Cells, Sending a Postcard, Jerboa Garden, Parrot Cage
Hard:
The Bottomless Closet, In the Cubicle, Rock on the Block