In reference to what I use for game development please see my FAQ page.
I have been looking at easing functions to enhance game play. One useful method I have used such a function for is acceleration on flight path. I used a slow acceleration function to slow the start of a missile when being launched. It has a better feel to the game when there is a slow acceleration.
A normal movement by linear speed accomplishes the goal of getting the object to its destination, but a more meaningful visual is to perform a slow accelerate. Using an easing function can accomplish this. Granted acceleration can be accomplished over time in a game by adding speed for every game step event. This is another method.
stepcount = 0;
speed=QUAD_EaseIn(stepcount, 0, max_speed, 1)
t = argument0/room_speed //step #
b = argument1 //beginning
c = argument2 //change
d = argument3 / room_speed //duration seconds
return c*(t/d)*t*t*t + b;
Hear is the updated result which IMO has a better feel.