I cannot promise a GOG release just yet, but I will be applying for the required publishing deal. If that goes through then yes. It would be a simultaneous release. The game is already on Itch (= DRM free version) and that too will be available on day 1 if I can help it.
@Nia_The_Cat Yes, you get to choose between the storefronts available. So that'll be Steam, Itch.io and hopefully a few more like GOG. GOG requires a deal with the site. I'll be applying but can't 100% guarantee it as an option just yet.
If you have any questions about Kickstarter just let me know. I'm hoping to raise enough funds in the next 20 hours, so I can finish this game. It's an all or nothing concept, so if we don't meet the goal then nobody actually has to pay anything.