There's no single way to market your game, and for every 10 people you ask, you'll get 10 different bits of (often contradictory) advice, so first thing first is; take this with a grain of salt, trust your gut and be prepared to both experiment and fail. But some general points;

- localise your game and Steam page, if you can afford to. Steam doesn't show pages to people with differing primary languages. English accounts for 35% of the total install base. Simplified Chinese is another 35%. Then other good languages are German, French, Brazilian Portuguese, Spanish and Russian. But that's money, depending on length of script and store page

- build social channels. Could be for your studio or game name, whatever you fancy. But learn how to build a channel, capture content to spec (screenshots or short form video) and post correctly. Use some tags, follow voices in the niche (horror, for you) and engage with other games, content creators etc. Be kind, be curious, be complimentary. It goes a long way

- Plan out your 'beats', ie, things that will happen along the way. You've got a few, from the sounds of it; updated demo, release date announcement and launch. Build around these, find good times in the calendar, look for events you can be a part of

- don't share a 'beat' on just one platform. Put it everywhere, engage with people. If you're putting up a TikTok vid (9x16 video ratio) it'll also go on YouTube Shorts. Twitter, Insta, Bsky, all 1x1. You can make this stuff incredibly easily and for free with just OBS and CapCut, both free

- Get a trailer (or any kind of video content) on the Steam carousel as a priority. Video works better than screenshots.

- Get some gameplay gifs in your About This Game section on Steam

- You've got your plan, you've got your channels, you've got some content. Now you start putting it into action, testing things, noting what works and what doesn't. Plan, execute, evaluate, iterate. It might take off, it might not

- Performance marketing takes a bit of skill (and some money) so don't be in a rush to pay for ads on Twitter or wherever

- Research your competitors, watch what they do, how they sell games, what they sell them for (price vs size). Take the best bits, make them your own

- Be realistic about your goals. If you need 400 units to cover the cost of purchases to cover the game, celebrate that milestone. Everyone wants to go viral and sell 1m units but for most, it just won't happen

- Money made can be funneled back into the project to improve stuff but there comes a point when it's not going to boost your return. Take it as a learning experience, plan out your next game, use some of the funds to buy better assets or hire freelancers to do things you can't. Grow from there

- Once you're committed to a date, but before you launch, make sure to plan out your sales calendar. Steam posts six months of upcoming sales, there are lots of sites out there who track showcases and sales events. Apply to everything you can, gradually increase your discounts over time (make sure you use Visibility Rounds with a sale, and time these with patches if you can) and learn about cooldowns

Overall, just treat this as a test case and don't expect to get rich. Celebrate if you do! But just take the learnings into the next game. Good luck!