+ Sprite: On step
-> Sprite: Push out of Sprite2 : Normal (use for slide)
-> Sprite: Apply friction of 0.5 to speed
+ MouseKeyboard: Key Right arrow is down
-> Sprite: Accelerate horizontal speed : 100
(orientation 45 degrees)
+ MouseKeyboard: Key Left arrow is down
-> Sprite: Accelerate horizontal speed : 100
(orientation 140 degrees)
Where Sprite is the player, and Sprite2 is the terrain.
Note:
You could make a Sonic type of game out of this by figuring out a way to adjust the orientation.