Missing a few stars
The panel's star count won't reach 250, and the star gate stays shut.
Nudge 1Where to look
Some stars are only reached late, with things found late: the far beach, the flooded chamber, the clouds, the two castles.
Nudge 2A stronger push
Thirty of them are in subgames, and the minecart can be ridden again.
Show the solutionThe whole answer, with a video
The stars page counts the stars of every place, and says where the hard ones hide. The ones most often missed: the trench's ten and the minecart's twenty, the four in the mines' flooded chamber, the clouds' highest ones, the castle's right side beyond the fire, and a few in the treehouse reached from below.