Rigidbody2D.velocityX

Description

The X component of the linear velocity of the Rigidbody in units per second.

This property allows you to read or write only the X component of the linear velocity of the Rigidbody without affecting the Y component if the linear velocity.

Additional resources: Rigidbody2D.velocity and Rigidbody2D.velocityY.

using UnityEngine;

// Ensure that the maximum horizontal speed moving right isn't larger than the configurable value.
public class Example : MonoBehaviour
{
    public float MaximumSpeedRight = 2f;

    private Rigidbody2D rb;

    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    void FixedUpdate()
    {
        // Clamp the horizontal speed.
        if (rb.velocityX > MaximumSpeedRight)
        {
            rb.velocityX = MaximumSpeedRight;
        }
    }
}