Final price of the sale, and I would recommend it.
Saying why is a bit hard, but I'll try a small swing at it. SOMA's two strongest elements are its narrative and atmopshere. The story has a lot of layers to it but ultimately deals with a very interesting yet simple question that it sort of runs with through the whole game; it doesn't really have a lot of plot twist, it delves deeper and deeper into its themes as you descend deeper into the ocean.
Being a Frictional game, there's a lot of things to interact with in the environment and fiddle around with. And deep in the sea, there are strange monstrosities you have to evade and survive. You spend little time getting chased but there's some stand-out encounters and a surprising variety among the game's monsters, in both what they are and how they behave, wven though the encounters are infrequent.
Game will make you think a lot, put you on edge at times, and there's some moments unlike anything else you'll experience in a game in this day and age. Without spoiling too much, one of the moments closer to the end of the game where you go to deep sea during an ocean storm and the following segments will last with me for a long time.