It's worth playing, no matter what your tastes: its twisting, cerebral plot made our list of the best stories in PC gaming earlier this year, and it's also on our best indie games list. You'll enjoy it even if you hate horror thanks to its monster-free Safe Mode, which was added last year (you can read Andy's interview with the devs about it here).
If you're interested, you should read Andy's full review—he called it a "masterpiece of audio and visual design", and said its underwater base was "one of the most fascinating, atmospheric spaces I’ve ever explored in a game". High praise indeed.
You can browse all the discounted games in GOG's Winter Sale here.