if (isLeftPressed) { speedX -= boost; x += speedX; } else if (isRightPressed) { speedX += boost; x += speedX; } else if (speedX > slowdown) { speedX -= slowdown; } else if (speedX < -slowdown) { speedX += slowdown; } else { speedX = 0; } x = slowdown + speedX; //пробовал x += speedX; // и так тоже x = x +speedX; checkBorders();