starseed

early game:
return to the hub-world with seeds and grow outwards to discover islands with different player-character behaviours, growth patterns, and other small mechanical tweaks.

mid game:
in the island worlds, grow out to the three-key locks (appearing as corruption blocks holding three stars), and reach them in the flip world while holding 3 keys to unlock a stage of designed challenges for that island world. complete the stage to 'finish' that island world.

end game:
finish all three-key lock challenges to complete all island worlds and then ???