klabundee in his example doesn't compare time or speed, which means if you move your finger really slowly across the screen, it will still be recognized as a swipe.
I would do something like this:
On any touch end
....Touch.Angle between 60 and 120 -> Move character down
....Touch.Angle between 150 and 210 -> Move character left
....Touch.Angle between 240 and 300 -> Move character up
....Touch.Angle between 330 and 30 -> Move character right
For more strict swipe recognition you might want to check if the time between touch start and touch end is less than, say 1 second.