Physical rewards are kind worthless for me and they put an unnecessary strain on the devs, who don't develop game as their main employment. It's costly, time-consuming and puts a mental strain on the devs who need to get all the items shipped out. If it's a developer team, that does video game developing as their main job, then that might be a little bit different. I also don't expect a game made by a single dev, who is also in a bind of hiring artists, to be put out in half a year.
Personally I'm not a patreon kind of person, due to my financial situation. I don't like to have many monthly payments to pay. But that's just me and I know devs who have some small success with their Patreon. And I also know that there are consumers/player who like Patreon. Tho I'm not going to lie. Sex sells. The majority of these devs are very focused on romance and erotic/sensual content, then combine that with a genre people just really like (high fantasy/farming sim).
They often come with a long established fan-base and are supplying a big-ish enough crowd with content they wouldn't get otherwise. Unfortunately realistic sc-fi combined with slow psychological horror and realistic art style is something a very small minority of female VN/Otome players thirst for.
I'd say you'd be having much much more success with the female video game player crowd or women, who like to watch TV series like the Expanse or read Sci-fi books. *cough* MEEEEEEE. I love Sci-fi. I grew up with playing city-builder, 90s adventure, RPGs, hack and slash RPGs, shooters like Unreal, strategy games. I love some good sci-fi games. There is such a big crowd of female Mass Effect fans out there, I bet they would love this! Anyway back to the target groups:
VNs are very resource and player friendly due to how they are "played". We read them and we just need to click some buttons. It's idiot safe for people who don't play video games and their PCs/Macs/whatever can easily handle a Ren'py game that doesn't come with 3D animations. Ren'py games can run on a potato. So the target demographic is definitely not just some VN/Otome players, who scrunch up their nose at everything that doesn't either look like anime or tumblr special snowflake red nose reindeer art style. That is important to remeber when approaching the book reader/movie lover crowd.
All of that doesn't mean you won't be able to finance your project via Patreon. I guess it depends on the scope of the game and how fast you want to put it out. And more importantly who do you market it for? Shoot for the female video game players, Sci-fi movie and book lovers.
I'm not trying to fool you with how important the target demographic is. I play Seven Kingdoms: The Princess Problem. It's a visual novel/otome/rpg hybrid/stat management/historical political drama. The hardcore userbase is just like me who grew up with video games and played nearly every Bioware title. The game is still in development, but people love it either way.
Then I'm part of multiple otome/female oriented visual novel groups. Whenever I post a project that looks stereotypical otome like in it's structure and has anime art-style, it gets a ton of likes. When I post something more "complicated" or intricate in terms of plot that doesn't necessarily come with anime artstyle, it gets barely 2 likes.
I wanna cry.
Anyway, Sylvertany made some good points when it comes to rewards or updates that may suit your expertise:
"You can write about what lead to developing Azimuth Gap, the inspiration, the difficulties, the research. You may not be able to write about progress on the script, but you can perhaps take a look at different aspects of the sci-fi setting you built and expand on them.
Authors who run a tumblr blog usually get asks about different scenarios or simple questions about the characters, how would they act, what do they think. You could think about accepting asks like this somehow on Patreon and answering them parts publicly and in parts just for patrons."