BGJ-2022.1/Assets/Scripts/Movement/EnemyVerticalMovement.cs

using UnityEngine;

namespace Movement
{
    public class EnemyVerticalMovement : EnemyMovement
    {
        protected Vector2 gravityForce = Vector2.right;

        protected override void Awake()
        {
            base.Awake();

            _rigidbody2D.gravityScale = 0f;
            gravityForce *= -Physics2D.gravity.y * _rigidbody2D.mass;
        }

        protected override void FixedUpdate()
        {
            _rigidbody2D.AddRelativeForce(gravityForce);

            if (IsPaused)
                return;

            Vector2 velocity = _rigidbody2D.velocity;
            velocity.y = moveValue;
            _rigidbody2D.velocity = velocity;
        }
    }
}