Hopping Mappy is an arcade game that was released by Namco in 1986. It runs on Namco System 86 hardware and, as the name suggests, it is the sequel to Mappy, released 3 years earlier. The game was ported to the Wii Virtual Console in Japan on June 2, 2009.
In Hopping Mappy players control the Micro Police mouse, Mappy, as he bounces on a pogo stick to run circles around pink cats, called Meowkies, which patrol either vertically or horizontally. There's also Nyamco, a cat who patrols in a zigzag pattern, but he needs to take occasional breaks. There are eight treasures the player must grab to complete a level, except on the bonus level where the player will just want to grab all the balloons he can. The main intrigue here is getting past a blockade of Meowkies. What is the best way to sneak by?
The player's controls are really simple: he can bounce in any of the four directions, the only places he can land are the centres of the checkerboard squares (making for very few locations overall), and he will move at the same speed as the cats. If the player pushes the accelerator button and runs around, he will go twice as fast. This is not always good - he can run into a bad guy, or it is tougher to turn.
Regarding turning, the player may want to do this in advance, just after he started jumping onto the square he wants to land on, if he is running away from Meowkies or trying to reach a square with a treasure first. It will ensure no time is lost. But if the player is trailing then obviously he will want to slow down.
There's another case where the player will want to slow down. Say he jumps in one direction and wants to pull back. He can, as long as his shadow is not touching an enemy's.
Source: Wikipedia, "Hopping Mappy", available under the CC-BY-SA License.