The '80s themed Netflix tie-in, Stranger Things 3: The Game, has been removed from Steam and GOG today. It was developed by BonusXP who currently has not given a reason as to why the game is being pulled. If you bought it, you'll still own it, but it will no longer be available for purchase to anyone who hasn't.
"Stranger Things 3: The Game will be removed from sale on Steam," developer SpectralLlama stated. "We're very grateful for all the Stranger Things fans that have traveled back in time with us to the Summer of '85 for this adventure through Hawkins."
If you go to the Steam page right now, you'll find that the 'buy' button has been replaced with a notice: "At the request of the publisher, Stranger Things 3: The Game is no longer available for sale on Steam." However, its community page is still available to peruse, keeping in-tact guides, screenshots, artwork, reviews, and more.
It's unclear if this is related to the Dead by Daylight news. For context, all Stranger Things DLC will be removed in November. Currently, there's two survivors - Steve Harrington and Nancy Wheeler- and a killer, the Demogorgon. They were added alongside the Underground Complex Map but, likely due to licensing, they will no longer be purchasable after November 17.
It is likely that the game's removal from Steam and GOG is also down to an expiring license, but the Nintendo Switch publisher that ported the game, En Mass Entertainment, shut down last year.
Nonetheless, Netflix is branching into games itself soon, including them as part of its service alongside TV and film, so we could see a new Stranger Things release soon enough.
For now, if you missed out, there's currently no way to purchase the game, anymore. That is unless you can get your hands on a limited physical Switch copy.