JoshVillaluz
Use Set vector Y and put a negative value (e.g. -128) to make the player bounce up.
You can also use Set vector X to make the player bounce away from the obstacle
Here's an example, that will bounce the Player back or forwards depending on where they are in relation to the Spike:
Set vector X = Player.X < Spike.X ? -128 : 128
Edit: Here's an example with higher values:
capx (r244)