I found that when I’m moving a character in a 2d world to a wall, and keep moving towards the wall, that both the player and the wall rotate slightly on the z-axis making player stutter left and right.
Now I’ve seen somewhere that you can lock all z-axis’ but I can’t for the life of me remember how it was done.
So, in short: How do I lock/freeze all z-axis’ of all objects(and objects to come!)
Assuming you are using Rigidbody or Rigidbody2D components both of them have the option. You can select it from the editor.
Here is the access through scripting:
On the other hand you cannot freeze them globally with the build-in tools (I think it would be bad idea anyway)
Cheers 
One (a bit hacky) approach would be to just surpress rotation by setting Angular Drag to a really high number (like 1000000).