Action would be the most difficult for me. Is that counted under "Soulsbourne Action"?
Easiest would be RPGs, strategy games, and sandbox simulators - Dwarf Fortress has the reputation of being one of the most difficult games to learn, but it's actually very simple if you start by isolating the basic survival mechanics and work out. You can probably master the game in 8 hours. Most strategy and RPGs are even simpler than that. RPGs, IMO, are the easiest genre - even action RPGs like Witcher 3 are quite easy on the highest difficulty levels (Witcher 3 Death March is only slightly more difficult than the basic difficulty), it's just a matter of character setup and understanding the mechanics. I also love these games :)
Next to easiest
Moderate: Platformer, fighters, racers. But, again, these depend on the game. Some will be easy to master in about 2-8 hours, but many take around 20 hours to master.
Moderate: Puzzle, I find these take quite a while to master, and even then you can improve an even more. 30-50 hours to master?
Hard: Action games, particularly older ones from the 80s and 90s. Some of these are insane! Ghosts and Goblins, FUCK that game :)
It's been 30+ fucking years and I still am nowhere near mastering it!
Or how about Fantastic 4 on Playstation?
Of course, there are many many exceptions, Turtles in Time was quite easy, for example.
I describe myself as a little dose of toxic masculinity.
