interesting take, just spent a bit of time on the first level and i have some notes to improve.
you need a Do Once node after Actor Begin Begin Overlap Event in the first rock because the Timeline of Set Actor Location keeps playing over and over again every time the player pawn overlaps the Trigger Box.
and you need to set mouse input mode to game only after the player closes the first explanation widget so the player won't need to click again to control his character.
and decrease Near Clip Plane so the player view won't clip through rocks.
Horror Engine is cool but it has some minor bugs that are easily fixable.