It might have contributed a bit, but I had similarly bad motion sickness with The Talos Principle, so my running theory is that the camera movement required for this sort of gameplay just reacts badly with my brain. And yeah, you should be really proud of yourselves! The atmosphere of the game was great, and I thought I spotted one of those 'using the environment to complete the path' style puzzles that I loved so much in the Witness before I had to dip, which is awesome!