Okay so maybe I'm overthinking this, but I played through this a bit ago and I can't help but wonder certain things about the method of "immortality" (which I assure you I find extremely interesting--this is such a unique spin on this concept).
But, well....I began questioning certain things. We shed skin cells daily (it's actually what makes up a lot of the dust in one's bedroom). The implication of not doing that, from my POV at least, would be a buildup of grime in the pores and all over the body.
The next thing is hair. Are all the humanoid creatures who choose this form of immortality doomed to be bald eventually? Because considering how much hair I shed in a week, if my hair stopped growing, I feel as though it wouldn't take too long before it was all gone. That would include eyebrows and eyelashes (both of which are your eyes main protection from things like dirt and dust).
Then there's the question of eating. I can't even begin to understand how that would work.
The other thing that I thought about was sickness. Forget any known autoimmune disease that exists in our own reality, this would be ten times worse. Any cells killed by a virus or disease would simply be lost. Sure, your body will probably be able to kill something like a simple cold before it would actually kill you, but it would cause irreversible damage to your body to do so. Not to mention allergies.
I also found myself thinking about the injuries and such we accumulate over time. Many people have calluses on their feet. I have to wonder how that would be impacted by this concept. Would people still even get calluses? Would our bodies just erode over time, instead? Our muscles would also wither away pretty quickly (as a relative term) simply due to use (and we wouldn't be able to strengthen them, either).
And I'm sure organ donations wouldn't do any good.
These are all questions I'd like answers to. But honestly? That just makes this so much more interesting to me. I mean, the concept is basically that humans have the thing that we've strived for the most in our grasp, but it comes at the cost of the biggest advantage of being a living thing--our ability to heal and regenerate. And the decision between those two things is something I don't think I could ever give a satisfactory answer to.