Descent from the mountain

Hello.
I'm trying to implement the physics of the game Ski Safari and Alto's Adventure.
I can not make a move from the mountain.
My player has a RigidBody2D

and a PolygonCollider2d for skiing(about standard settings). The floor has the Edge Collider 2D.
It is possible to make the floor perfectly smooth, but it is rather difficult if the number of floors is large.
The problem is that the movement in these games is very smooth, there the player seems to stick to the floor. In my case, the player shakes a little when moving, what do you advise? Maybe I have an extremely wrong approach?
You can download unitypackage with my project(Scene: SampleScene).

Code (CSharp):

1. public class Player : MonoBehaviour {
2.  
3.     [SerializeField]
4.     private float speed;
5.     [SerializeField]
6.     private float impulseAddForce;
7.  
8.     public bool isGrounded;
9.  
10.     private Rigidbody2D playerRB;
11.  
12.     private void Awake()
13.     {
14.         playerRB = GetComponent<Rigidbody2D>();
15.         isGrounded = false;
16.     }
17.  
18.     private void FixedUpdate()
19.     {
20.         if(playerRB.velocity.magnitude < speed && isGrounded)
21.         {
22.             playerRB.AddForce(new Vector2(1,-1) * impulseAddForce,ForceMode2D.Impulse);
23.         }
24.     }
25.  
26.     private void OnCollisionStay2D(Collision2D collision)
27.     {
28.         if(collision.transform.tag == "Ground")
29.         {
30.             isGrounded = true;
31.         }
32.     }
33.  
34.     private void OnCollisionExit2D(Collision2D collision)
35.     {
36.         isGrounded = false;
37.     }
38. }

 

Did you try apply physics material to the contact surface?

 

With Material Physics 2D looks better.
But there is no sticking effect, that is, when the speed rises (not significantly), the player tears off the surface, maybe it's worth playing around with the settings(gravity, mass)? And also there were jerks when trying to increase the speed of the player, if speed rather small, I think it's because of the vector in AddFors

Code (CSharp):

1. playerRB.AddForce(gameObject.transforn.right * impulseAddForce,ForceMode2D.Impulse);

, but how to fix it?