Box Jenga
Box Jenga inverts the dinner-table classic: instead of pulling blocks out, you drop them on. Boxes swing overhead on a moving arm; tap to release, land them square on the stack, and build the tallest tower you can before physics files a complaint.
Every off-centre landing adds lean, and lean is forever — a sloppy third box is what actually topples your fifteenth.
Tip: wait for the arm's direction change. It slows for a beat at each end of its swing, and that's the drop window. A deceptively pure entry in our timing games tag.