Wall collision when jumping in 2D demo

I downloaded Tower Bridge demo to find out how to create some 2D game basics and I used some scripts etc. But I can’t achieve this effect - in demo, when you jump up and right AND you hit the wall, the player slides down to the ground. However the same doesn’t happen in my game. I use simple 2D box colliders on my walls and my player controller script is following:

public class PlayerScript : MonoBehaviour {
	[HideInInspector]
	public bool facingRight = true;

	public float moveForce = 365f;
	public float jumpForce = 200f;
	public float maxSpeed = 5f;

	private Transform groundCheck;
	private bool onGround;
	private bool jump;

	void Awake() {
		groundCheck = transform.Find("groundCheck");
	}

	void Update() {
		onGround = Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));
		if(Input.GetButtonDown("Jump")  onGround) {
			jump = true;
		}
	}


	void FixedUpdate() {
		float h = Input.GetAxis("Horizontal");

		if(h * rigidbody2D.velocity.x < maxSpeed) {
			rigidbody2D.AddForce(Vector2.right * h * moveForce);
		}

		if(Mathf.Abs(rigidbody2D.velocity.x) > maxSpeed) {
			rigidbody2D.velocity = new Vector2(Mathf.Sign(rigidbody2D.velocity.x) * maxSpeed, rigidbody2D.velocity.y);
		}

		if(jump) {
			rigidbody2D.AddForce(new Vector2(0, jumpForce));
			jump = false;
		}

		if (h > 0  !facingRight) {
			Flip();
		} else if (h < 0  facingRight) {
			Flip();
		}			
	}
	
	void Flip()	{
		// Switch the way the player is labelled as facing.
		facingRight = !facingRight;
		
		// Multiply the player's x local scale by -1.
		Vector3 theScale = transform.localScale;
		theScale.x *= -1;
		transform.localScale = theScale;
	}
}

Yet the player object is sticked to the wall as long as I hold the keys down. Thank you for any advice.

Easy fix, just give your walls a physics material with no friction or bounce and it won’t stick to the wall.

Thank you very much, sir!