1- the canvas size for the start screen and death is bad for me I am not sure if that is with all it related to your screen I have 1920x1080
2- the player is blur but other things like NPCs is not blur
3- you use unity right, Go to projects and create physics material 2D set the friction 0 so and add the physics material 2D to the player Rigidbody 2d
Do that to fix player sticking in the walls
Link-
if you don't find physics material 2D then right click in the project go to create then 2D then Physics Material 2D.