SOMA’s ending is the last twist of a game with some impactful ones. From the beginning, where you are, apparently, transported from you hometown to a strange underwater facility, to the moment when you discover your new nature or the acknowledge of the fate of the humanity and PATHOS-II members themselves (LINK), those moments and twists build a fascinating science fiction story.
The final question is about what makes you human or even more, what makes you YOU. Is a copy of your consciousness to another body, creature, memory or machine less YOU? The game plays a bit with this because when you transfer yourself the first times, you continue playing with the new one (LINK). In the end, when you transfer to the ARK, the creation from the last survivors to preserve humanity’s legacy after a comet destroyed Earth’s surface. In that final moment, the game stays at first with the old one, just to show again (thanks to the Catherine’s voice that has explained the same before) that transferring your memory does not delete the original one, is a copy, not a cut. Then, there’s an epilogue when you see the fate of the last copy: