Combat Tips?

[Sebastian Peril]

I was wondering if you guys could help me with some suggestions as I am CLEARLY missing something here. I've read that this game is supposed to be one of the easier Souls-likes but I am getting absolutely destroyed by the first boss (Grisha)

I've finished Dark Souls, Dark Souls II, Dark Souls III, Nioh, The Surge, Code Vein, Lords of the Fallen, Elden Ring, Salt & Sanctuary (and probably more that I can't think of off the top of my head) and Mortal Shell is by far giving me the most trouble out of all of them. I'm obviously missing something necessary for the combat to click but so far it just feels sluggish and unresponsive.

Teach me things! :)

[ēdiššu]

As far as I understand this combat in this game is about hardening, parrying, and utilizing shell abilities.

First of all, learn to use hardening effectively — I suppose this is meant to be instead of blocking.
Reach Fallgrim Tower (the first delapitated building you will see, just straight ahead), release the prisoner, and talk to him — you will get an item for parrying. Upgrade it to heal via parrying blows. Mind that parrying is slightly different, more predictive (parry before attack begins, but when the animation starts) than in Dark Souls (parry before attack reach you, but mind the parrying item speed). Not all enemies all parryable, but most of them are, including bosses.
Remember about the healing mushrooms than you can collect.
You can unlock kicks via sester Genessa which might be usuful to you at the beginning.
Seek rare acids that are used to upgrade weapon damage.

[Sebastian Peril]

Lots of information there! Thank you very much, I'll take it with me when I next boot the game up :)

[Alfred Kodani]

Part of the fun is figuring out how the game works. There are a few things I'll note though.

• Your weapon has heavy and light attack combos. Watch their timing, range, and sweep.
  
• Most enemies telegraph their moves. You will learn these by dying.
  
• Avoiding enemy attacks can be done by parrying, hardening, dodging, or stunning them with the right attack/circumstance.
  
• Harros and Solomon are the best shells for beginners.
  
• Don't be afraid to run away if you're desperate.

[Napalm®]

Running jump attack. Just that. For any enemy and/or boss. When used with hardening it's basically a cheat. I remember when I discovered it I felt like I spoiled the game for myself, so I tried NOT to use it all the time, but if you're having problems try it..

[Mr. September]

I took down Grisha after I already maxed out my weapon (Hammer and Chisel) in terms of damage. You can just dash in, get the chest and get out of there (through a tunnel or just the way you came in) anyway. You aren't missing a lot if you don't kill it (maybe apart from the Tar), as far as I'm aware.

The combat is methodical and 1v1 is encouraged for the most part (as far as I can tell). Try luring enemies one by one (by playing a lute or just aggro'ing them yourself) and let them attack thin air to see their movesets first. This isn't necessary for weak enemies, but even they can overwhelm you easily if you are not careful. Even the lightest weapons have decent stagger potential against most targets.

You can always Harden (when attacking or between attacks) to throw the enemies off and punish them. I usually go for an attack or two, then I let them hit me mid-combo, so they recoil, and I land a few more hits, then roll away to recover Harden.

Parrying is also a viable strategy, if you practice it a little to land it consistently. From what I've seen so far, the amount of frames is fairly generous, and you can always Harden to negate the damage if you miss a parry. Remember that the seal emits sound and light when an unparryable attack is targeting you. It rarely fails at that, but works for the most part.

All in all, this is a far slower game than the DS games. Even the fastest weapon is very slow compared to fast weapons in FromSoft titles. I recall having a lot of trouble before, maybe because I was used to the handling of DS3, but this time I had almost no issues, apart from getting lost and going in circles, .

Found these two videos (and watched them both myself as well) and I'm sure they will help you. They did help me since I learned parry timings and other various info I didn't know.
How to Parry in MORTAL SHELL
15 Weird Tips for Mortal Shell Noobs...