Recommendations to get really Meta and mess with my players?

This year marks the 10th anniversary since my friends and I started playing Dungeons and Dragons. I will hopefully be DM'ing (first time DM for an extended campaign that's not a one shot) at some point this year and want to have it be an epic time. I've been planning an arc that will primarily feature the Space Clowns from Spelljammers and have some shenanigans that will involve my players touring through a fun house. As they delve deeper into it, I want to have it slightly get more meta and fourth-wall breaking as the clowns try to mess with the sanity of my playerss. The goal is to have a similar vibe to the film "In the Mouth of Madness" and the video game "Eternal Darkness".

Any mechanics, ideas, or homebrew would be greatly appreciated!