Plank Unscrew

A full-3D wooden puzzle with no buttons. A board holds stacked, overlapping coloured planks pinned down by shiny metal screws. Tap a screw to spin it out and pop it into your tray. Take out every screw from a plank and it drops away. Leave a plank hanging by a single screw and it swings down like a pendulum, which can free the screws of the planks under it. A screw that sits under another plank cannot be touched until that plank is out of the way, and your tray only holds a few loose screws at a time, so think before you tap. Every puzzle is built backwards from a real solution and checked by a solver, so each one can be cleared. Twenty-five boards grow from two planks to a dozen. Clear one with no undo and fast for three stars. Beat board 25 to become Champion, then keep going in endless mode. The Daily Challenge and friend rooms use one fixed board for everyone and rank the fastest, cleanest clear.

How to play

Tap a screw that is not covered by another plank to unscrew it into the tray.
Empty a plank of screws to make it fall. Leave one screw and it swings, so you can free what is beneath it.
Clear every plank. Tap the small undo arrow beside the tray if you jam yourself.

Tips

Screws that drop a whole plank do not use a tray slot, so look for planks with one screw left.
Do not fill your tray with screws from planks that are still stuck down; free a plank first.
A swinging plank sweeps over its neighbours, so wait for it to settle before you plan the next tap.