Record a short route and coordinate with its repeating shadow to open doors.

Deduce hidden atoms from rays that pass, bend, reflect or hit them.

Rotate groups of four numbered tiles until every row is in ascending order.

Wrap complete rows and columns around a numbered board to restore their order.

Roll a cube and exchange colors with floor tiles until all six faces are blue.

Assemble twenty original pixel pictures from interlocking pieces.

Decode twenty original phrases with a consistent letter substitution.

Find a five-letter word from position and letter feedback in six guesses.

Find as many connected English words as you can in a three-minute letter grid.

Use linked equations to deduce the value of every letter.

Identify a counterfeit coin using a limited number of balance-scale weighings.

Place vampires, ghosts and zombies to satisfy clues seen through mirrors.