posetcay: It's kinda weird how Life&Death - Intermediate collection has a higher difficulty rating than this collection.
d4rkm4tter: I calculated the average difficulty of all problems in each collection and put them on a range from 1 to 10. The last time I did this was March this year though. I'll give this an update.
On top left, after C19 D19 E19 B18, playing the atari first at E18 shouldn't be marked as wrong