Which game engine did you use?
If you only need to slow the ice cube down, a good way would be to use a "speed" variable that you would multiply to a normalized direction Vector. I'm using Godot, so it goes like this in Gdscript:
var speed = 8
var direction = Vector2(1,0) //it means that it goes right. You would check for input controls to see if you're holding left or right
move_and_slide(direction * speed) //this would be run every frames and it moves the block in the physics of my game
It would give a Vector2(8,0) which means 8 pixels every frames to the right (X axis). If you want to move the ice cube faster, you only need to change the speed value to something bigger, for instance 16 which would change the speed to 16 pixels every frame. That would not slowdown the enemies, the backgrounds animations, etc! just the movement.
Basically, that's how I handle movement in my games. It's also useful if you want to implement a dash for example, you can change the speed for 1 second exactly (so you're faster for 1 second and then it drops back to the normal speed) without having to recode your movement just for this mechanic.