Polo 'n Friends

I feel like being an indie / individual developer ( no sponsor / no commercial / all for free) who is adventuring game development  since September 2025 to create a game in Godot for my grandchildren. My grandchildren introduced me to “Sprunki”. However, you can only move icons around (drag'n drop) to create melodies. I imagine a regular game in which you navigate the basic character Polo through a 2D world (jump and run style, similar to Hollow Night in terms of graphics and movements), find abilities, defeat enemies, and collect points (musical notes) in order to develop the character and ultimately defeat a boss to advance to the next world, where you then become a different Sprunki character... who then goes through the same logic but different world as Polo  until, at the end, the full “orchestra” plays music again.