You can use Touch.SpeedAt, Touch.SpeedForID expressions to detect swipes, and Touch.AngleAt or Touch.AngleForID expressions to get swipe angle. Then use a condition like "Is between angles" or "Is within angle" to check if the swipe is closer to horizontal or vertical line.
Another way is to save Touch.x,Touch.y on touch start in a pair of variables, and then on every tick compare the angle from touch start coordinates to current touch position.