conundrum
background
black
brain
challenge
concept
deadlock
decision
design
difficult
direction
education
entrance
entry
exercise
exit
find
game
geometric
go
graphic
illustration
isolated
jigsaw
kid
labyrinth
leisure
line
logic
maze
mental
pattern
puzzle
rebus
rectangle
riddle
right
route
scheme
search
shape
solution
square
success
tangle
task
thinking
way