I really enjoy playing Spirit Island and highly recommend it. It's my first more complex game and it's a blast!
My favorite game is probably Cosmic Encounter, and just like Cosmic Encounter has asymmetric alien powers that change up the game every time you play, Spirit Island does the same with spirits. The game feels practically brand new with every spirit you choose. I explain the game to new players as pandemic levelled up.
My only complaint really is the complexity. It both makes it really fun but also a potential barrier to entry for some, and certainly not a game for every situation. But I have to say that regardless, I still love it. It has jumped up to one of my favorite games even though I tend to prefer competitive games.