Algodoo

Snake is making a simple sine curvature and every next body piece is slightly delayed from previous

Goal: eat the mouse

Advanced controls:
W/S - timing (faster/slower/reverse)
A/D - frequency (amount of curves)
UP/DOWN - amplitude (width of curves)
RIGHT/LEFT - steering

You can see the sine wave made by sideways forces while going straight
(erase planes and set camera to follow snake)
Normally it is controlled by 4-axis joystick,
and it is really easy and precise, you can also make some stunts, attacks, quick turns etc.
But because most of people don't have 4-axis joystick, this is keyboard-friendly scene