Hourglass
From Vanishing Point Wiki
How to solve the puzzle:
SPOILER
Start the time.
Run start two more times until all hourglasses are empty.
Flip the 12 second and 4 second hourglasses and press start.
Flip the 7 second and 4 second hourglasses and press start.
Flip the 7 second and 4 second hourglasses and press start.
The puzzle will be solved. :)
Solved puzzle:


