This wiki explains everything in Elsewild in plain words. Every number on it comes from the game itself (version 0.14.60): the items, drops, costs and stats are read straight out of the game, and the guides were checked against it.
Spoilers
The wiki explains every land, creature and boss. It does not explain the game's ending: what happens after you hold all five Jewels is left for you to find.
Keys
Wherever a page names a key, it shows the key for how you play. Use the keys button at the top to choose keyboard, controller or touch.
Play
Elsewild is made by Eeriecast, LLC. Play it at elsewild.io.