The reward structure here isn’t so much the weapons or the experience, but it is instead the knowledge that nothing truly threatens you.
There will be no enemy in the game you cannot handily defeat with enough patience and proper use of your shell’s abilities.
It’s a satisfying way to play because when you reach the final boss, you know how to approach every attack and deal with every mechanic. In Mortal Shell, unless you want to handicap yourself severely, you must specialize and “git gud” with a single kit. In a game like Dark Souls, by mid-game, you can use almost anything with some degree of efficacy, though favoring a single stat over others usually leads to better damage, for example. This design philosophy of Mortal Shell favors mastery and specialization over an all or nothing approach.
By game’s end, you’ll probably have enough to fully upgrade a single shell and most of one weapon. You’ll be reliant on consumable items for them. Enemies don’t drop much of either, bosses included. There are two experience types in Mortal Shell - Tar and Glimpses - and you’ll need a lot of both to unlock even a few of the "cheaper" abilities. Leveling your shell is expensive, as well. You’ll want to decide which weapon you want to play early and stick with it. Resource management also plays a vital role in how you progress, as upgrade materials are more limited than in other similar games, and farming them before the end-game is almost impossible. Strategy is paramount, no matter how you want to tackle the game. With each of the four shells geared toward a particular playstyle, and all four of the equipable weapons eating your stamina for dinner, every action takes additional forethought. Its upgrades focus on tanking hits and dealing massive damage. The heavily armored cleric, on the other hand, has an enormous health bar but minimal stamina. Tiel, the Acolyte, the game's thief-looking shell, has a large stamina bar, but low defense, and their skills are built around speed, poison, and damage mitigation. Instead, you upgrade each shell with a set number of upgrades that grant passive and active abilities keyed to the theme of the shell itself. Each of the five shells has set health, defense, and stamina values that, even in NG+, can’t be altered. There are no “stats” in the traditional sense. Mortal Shell’s shell system, a kind of static, class-based mechanic, is an ingenious way to avoid balancing a complex RPG while still offering a satisfactory progression experience with enough depth to last dozens of hours. Mortal Shell Review: Stepping Out of the Shadows It’s a game made with love that has some rough edges, but it will scratch every Souls-like itch you have. There are no extremes here: the “bad” doesn’t come close to dealbreaker-status, and the good is plenty enjoyable without shattering expectations. That said, the combat, shell system, and boss fights make up for some of Mortal Shell’s weaker elements. Many of its characters lack any kind of robust backstory, it’s various environments act only as arenas, and some of the enemy mechanics are more frustrating than they are elegant. Some of the ways Mortal Shell iterates on that formula are to its detriment as well. Both its greatest strengths and weaknesses come from its reliance on the template laid down by FromSoftware.