It is spawning Rigid bodies with spherical shapes that move down a slope using in game physics. The objective of the game is to avoid them, but I do not know how to make them cause damage on Kismet...Can anyone help me with this?
Have you tried attaching the spawned actor to a touch event? So that the touch event is fired when a sphere touches you? If that works you can simply use a Modify Health node that deals enough damage to kill the player.