The payoff was Azure's friend card, and the crown is for finding every item+friend (well done!!) If you have ideas on rewarding players better please let us know!
Thanks so much for your thoughtful and fair feedback!
I'd just say for little side quests like that you just give cosmetics. Whether it be just a color swap or letting the player play as Bones, (I really like Bones, he's my favorite! Was sad he didn't have a spot in the demo ): ) Like there, you could've given Maxwell an Orange spacesuit, because, you know, Orange Island ;). Just the little stuff. That's all.