float x;
float y;
float easing = 0.05;
void setup() {
   size(640, 640);
 noStroke();
}
void draw() {
 background(#FF00CF);

 float targetX = mouseX;
 float dx = targetX - x;
 x += dx * easing;

 float targetY = mouseY;
 float dy = targetY - y;
 y += dy * easing;

 rect(x, y, 66, 66);
}