This one was definitely from the 80s; a comedy that I don’t recall being particularly funny or high-budget. I can only remember a few details, but here you go:

• The protagonist was a typical American teenage boy approaching manhood.
• At some point, he comes into his powers and gains control/obedience/worship of his parents. In particular, his mother makes his favorite food (cheeseburgers)  for breakfast (might be borrowing this scene from Twilight Zone: The Movie, but that isn’t it)
• For at least some of the film, the protagonist is accompanied by an attractive female agent of whatever incumbent force (Satan? evil wizard?)
• In the final confrontation, the protagonist defeats the antagonist in a scene involving opposing locomotives. There’s a smiley face central to this scene, but I can’t recall its context.