These are Time 1, Time 2 and Time 3
This example has proven very useful to me in game development, because sometimes you can't catch things at a normal speed. For the high speed mode, it is useful when you have to arrive to a certain point of the game very fast, for example.
Also, you can use a shortcut to show some sort of lame UI to present useful values that you want to change in realtime. Maybe the parameters of a effect. This way the artist can fine tune the parameters of the effect to achieve the desired result.
You can set a shortcut to go to each level (LEVEL1, LEVEL2, whatever), or enabling immunity to check the behavior of the enemies without worrying of being killed, ...