Stuck on second tree

Hello. After beating the first level I get stuck on the stage selection screen. I can only restart the level again. And I don't receive any stars even through I collected the fifteen bones.

how can you lose hearts? is there any combat? and what happens when you lose them all?

Does anyone know how to contact the dev team? Is there a discord server or a email set up?

Do you plan on implementing Steam Achievements?..Pivo looks great and I would love to see achievements added, thank you in advance for your time and best of luck with this and future projects