It's surprising how simple but satisfying this is. I really did feel the struggle of Sisophys. The random generation made my torment feel entirely intentional, not just situational. The "inspirational quotes" were especially demoralizing, as if my pain was somehow virtuous. And when I noticed more decimal places on my progress, I really felt like the system was rigged against me >:)
One thing I do wish is that it is easier to get back behind the rock. It never felt like I could outrun it, so the "grace period" felt unnecessary.