Drop the seven classic cube pieces into a target solid, working with gravity instead of against it, nothing floats.
You have seven small interlocking pieces made of cubes and a ghosted target shape to fill. Select a piece, rotate it to the orientation you want, then drop it into a column. The piece falls and must come to rest on the floor or on another piece, so the order you stack in matters. Fill the whole shape to win.
Soma Stack is a take on the seven-piece cube-dissection puzzle, with a gravity rule that adds a fresh challenge.
The seven pieces are the Soma cube, devised by the Danish polymath Piet Hein in 1933 — reportedly during a lecture by Werner Heisenberg on quantum mechanics. They are every shape of at most four unit cubes that contains an inside corner, and they assemble into a 3×3×3 cube.
The original rule here is gravity: a piece is dropped into a column and must come to rest on the floor or on another piece.
That converts a dissection puzzle into a scheduling one. Hein's cube can be built in any order because pieces can be placed anywhere; forcing every placement to be supported means a correct final arrangement can still be unreachable, so the question becomes which piece has to go in first.
Soma Stack is an original free browser take on the classic seven-piece cube-dissection puzzle, with a gravity rule that turns assembly into a stacking-order challenge. Built in-house for PlayPendium.