Mortal Shell is called 'Mortal Shell' because there are Shells in the game that basically act as classes: you find the right Shell for your play style, then you set about strengthening it. But YouTuber Esoterickk has managed to beat every boss in the game without wearing any Shell. It's a bit like finishing Dark Souls without levelling up.
Should the game be renamed 'Mortal' then? Probably not, as Esoterickk has also managed to beat every boss without taking damage. That's a no Shell, no damage run, which is pretty impressive, especially as bosses will smite you in one hit if you're going Shell-less. You can watch all the boss encounters in the video below.
This run is technically different to an Obsidian Form Shell run, which is a hardcore difficulty that grants you a useless obsidian-hued Shell, and takes away your ability to acquire other Shells.
"I'm unsure what exactly is different about No Shell vs Obsidian Shell as they both appear to function the same," Esoterickk writes in the YouTube description. "But I decided to do a run without using a shell at all and seeing what it was like."
They continued: "To be honest, it actually felt easier than my first playthrough due to how much stamina you have and seemingly never run out. Coupled with your weapon skill building up much faster than before, it makes most fights a breeze. After a quick look at some Obsidian videos, it also appears to be the exact same in regards to stamina, weapon skill and boss abilities."
Mortal Shell is well worth playing. "Enjoyably tough and esoteric, if a little uneven, Mortal Shell is a decent debut from Cold Symmetry," Rick wrote in our review.