I am going to answer that question with a definite yes because it is clearly based off of the Dark Souls series. It is based on the games, but the way the developers crafted the game is very different from an actual Dark Souls game.
From the beginning of the game, there is a tutorial showing off the mechanics and how to play, but Dark Souls doesn’t have anything like that in its series. There are a bunch of similarities, but also many things that make it stand apart from anything like it.
The Shells you can find is one of the ways it is different. So basically, there are 4 different bodies you can “possess” and they each have a strength and weakness. It is pretty much like having custom classes with the presets already there for you to choose from.
You can also play the game without any shells to make it even harder for you. The only downside to doing so is that you only have a sliver of health and any enemy to hit you will kill you. With a Shell equipped, you have armor and a second chance at possessing your body again and regaining all health.
There are no bonfires in the game, which means there are large areas you need to restart if you end up dying in each of them. Eventually, if you upgrade a Shell enough, you can buy a special mask in which you can teleport to areas you have awoken Sister Genessa, but it is hard to find all of the areas she is in.
It is also very difficult to upgrade a Shell early on in the game. The Developers was a huge fan of Dark Souls, so they pretty much made a game that is similar but won’t really be a contender. It is a Dark Souls clone, but a great one at that.
The Game is Short
The game is not really long in any way. It took me about 11 hours in total to beat the final boss, but the game is very satisfying just like all the Dark Souls games are.
I did play all the Dark Souls games, so I know if a game is good or bad when it comes to Souls-like games. The Surge and its sequel are a couple of games that really impressed me with the title of Souls-like and almost felt like something different entirely.
Lords of the Fallen was also really good and there was Hellpoint as well. I really like it when smaller developers take a specific genre and put their own spin on it. That is what Mortal Shell was like for me.
If you have not played Mortal Shell, I would definitely say that this game is worth playing. This is not a Buy or Pass so this is my opinion, $20 is a great price for this game, so I would wait for a sale or if you have a coupon to get it for less money, use it.
If you are a fan of Dark Souls, you might really enjoy the game. There is a Demo of the game you can try before actually buying it if you are really worried about you not enjoying the game. Give that a shot and try it out.