Watch Way Weirder TV Than Your Players Will Endure, and STEAL EVERYTHING.
If I have a GMing style, it's "Steal everything you can, but never let your players know what you're stealing from."
One of the strongest sessions my home crew ever played was in Rogue Trader, and I had watched Season 5 of Doctor Who before anyone else. They went to bed one night during warp travel, and woke up on a strange ship with a constantly changing layout. Occasionally they would encounter these beings that would say something ominous and foreboding, but the moment they broke eye contact with the creature, they remembered nothing. So they had to stumble around some vessel of completely unknown origin, pressing buttons and jiggling with wires to open different pathways and never knowing where they'd end up next until they got to the bridge. There, they opened the exterior shutters and saw they were DEEP in the warp, and confronted a swirling vortex of terror. Soon afterwards, they woke up back on board their regular vessel.
TL:DR : using the gimmick of the Silence from Doctor Who to unsettle and completely wig out my players really helped unbalance and disorient them in the middle of essentially a space haunted house nightmare. And it worked especially well because they didn't know the rules, and I did.
taking something extremely silly and playing it totally straight can work as well.
I've run multiple sessions and storylines straight from Red Dwarf with a couple of Starfleet crews before to which they were none the wiser, and they flowed beautifully. Red Dwarf is some surprisingly insightful sci-fi when it wants to be.
Things are only as serious or silly as you can get the players to take it, you can absolutely do the goofiest shit and have everyone take it at face value if they're invested enough
And the real answer to ‘how do I get my players invested’ is always to never tell them where you’re getting things from, and to present what you’ve got earnestly. Never subvert your own fiction.
I have run bits of APs for games in entirety different settings and systems before and it works phenomenally well if you’re willing to just do it and accept improv to cover the gaps the premise change might entail, and it saves so much work if done right.
