My early sense of the game is that it is an atmospheric story driven first person puzzle game a bit reminiscent (for me) of a Gabrial Knight game or Myst.
The Kickstarter page (linked below) has a demo and gameplay videos folks can download to get a sense of the game.

I've been in contact with the developers regarding release options and they had the following to say (message posted with permission)

"Thank you for your interest in The Lighthouse. We plan on initially launching on Steam simply because we were Greenlit and we are familiar with their platform. We know once we're finished we can put the game on without much trouble.

We are absolutely interested in GOG.com and other DRM-free game platforms as well so be on the look out for more announcements as we near completion on the title! Thank you so much and if you have any questions for us, let us know! And don't forget to try the demo! =D"

The Kickstarter has 23 days to go as of this posting, so if it sounds like your cup of tea head on over and give it a look. With enough support it could be another fun addition to your GOG library :)

The link: https://www.kickstarter.com/projects/shadowknightsstudio/the-lighthouse-thriller-game?ref=profile_created