(The 144Hz screen was the problem, if I play on my 60Hz screen the game speed is normal).
Little tip : Never sync the game update to the framerate, it will cause game speed issues if the screen has a different framerate than the usual one (60Hz), it is a famous problem in games like King of Fighters : https://steamcommunity.com/app/222940/discussions/7/358415738200401557/
yep I got the problem, in unity i used Update constructor to do this job which created this problem. I think I have to replace using couroutines maybe. Thanks for finding the issue as I had the same issue when I was testing the game. Actually in that high speed the ball might cover long distances but the ground may not reach that extension. That is a result of the high speed of the ball. Otherwise it would be fine under normal cases. Thanks a lot for playing the game I have learnt something important. Thank you !! 😁