Check: http://store.steampowered.com/app/293240
Every Tick: Player > Platform Behavior > Set Angle of Gravity > angle(Player.X,Player.Y,Planet.X,Planet.Y)
Every TIck: Player > Set Angle > angle(Player.X,Player.Y,Planet.X,Planet.Y)
Player is simple player controller with platform behaviour
Planet is solid shape with 'rounded' polygon collision. If you look at your example while you're running you are actually going up hill then downhill then uphill then downhill.. Those are the peaks / points in the collision shape.