Problem with slide

What exactly do you mean by "a vertical slide"? What changes in acceleration and/or velocity are you wanting? What response do you want from each key while they are held down? and what should happen when they are not held down? explain each individually.

In my game there is the player on a fixed x-coordinate and from the right side cars spawn that move backwards and the player has to dodge them. I want it so that when i press "up" the objects y-coordinate changes to the top of the display (minus in coordinate system). When I stop pressing the button there should be a "run out" so the player cannot stay on a specific point. At the same time its important that when I press the "down" key this "run out" stops or accelerates in the other direction (plus in coordinate system). Velocity: should go smaller when the button is not pressed Acceleration: changes in acceleration are not necessary Any kind of form in between what i described will be helpfull, thanks for youre support man!

Basically, what you are asking for is that the keys act as accelerators in opposite vertical directions and there is a drag factor applied to the object. Without a SmoothMover class, you can simply do something like this: