It Came From the Late Late Late Show is a humor/horror role playing game where you character is the actor whom has a role in a B movie. It is published by Stellar Games and was written by Bradley K. McDevitt and Walter H. Mytczynskyj. All the links to the sites for this game are gone and dead, so I don’t have any good way of linking you to this game. The only place I have found the English version of this game available is on ebay, and the sellers tend to want a lot for a niche game from the late 80s. The German version is available on PDF from drivethrurpg.com.
This is one of the hidden gems from the late 80s early 90s era of RPGs. It is a very simple system to pick up and run with little requirements for players to learn the rules beforehand. A very good character sheet/introduction to the game can be found here. The one I currently use is a blatant rip-off of this one, so might as well link the original the author.
The PCs are actors acting in a B movie, so the fourth wall takes a big step back. There will be times the PCs are in their role of actors and times that they are in the role in the movie. Those jumps can be sudden and silly. The PCs don’t like the way a combat is going, they walk off the set and argue with the director. A PC about to take a big hit, call the stunt double. I like to tell the players that their actor is a little too good to be in this movie, but a real world problem has caused them to take a lower roll than their starpower would normally suggest. Just to make sure the PCs are unmotivated or over motivated to make this movie work.