a 2D free movement playercontroller

playercontroller.cs

/*
 * playermovement.cs - attaches rigidbody onto gameobject in editor via RequireComponent, checks inputAxis via Input Axis Names (defaults to Horizontal, Vertical). 
 * Intention is to move a 2D sprite across the screen via Rigidbody2D
 * All properties are private with defaults values. If you need to change a property use the methods to adjust them
 * Note: This does not attach a collider or check colliders in anyway. That should be handled separately.
 */ 

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(Rigidbody2D))]
public class playermovement : MonoBehaviour {

	private float m_MovementSpeed = 10.0f;
	private bool m_CanMove = true;
	private Rigidbody2D m_Rigid;

	private string horizontalAxisKey = "Horizontal";
	private string verticalAxisKey = "Vertical";
	private float m_hAxis, m_vAxis;


	// Use this for initialization
	void Start () {

		m_Rigid = GetComponent<Rigidbody2D> ();
		//this is double checking we have this component even though Unity requires it from our RequireComponent above
		if (m_Rigid == null) {
			Debug.LogError ("Player Rigidbody2D is: " + m_Rigid);
		}

	}
	
	// Update is called once per frame
	void Update () {

		//can the player move? If set to false return 
		if (m_CanMove == false) {
			return;
		}

		//get the axis values
		m_hAxis = Input.GetAxis (horizontalAxisKey);
		m_vAxis = Input.GetAxis (verticalAxisKey);
		//make the player move
		m_Rigid.velocity = new Vector2 (m_hAxis, m_vAxis) * m_MovementSpeed;
		
	}

	/// <summary>
	/// Sets the movement speed.
	/// </summary>
	/// <param name="speed">Speed.</param>
	public void SetMovementSpeed(float speed)
	{
		m_MovementSpeed = speed;
	}

	/// <summary>
	/// Can the player move?
	/// </summary>
	/// <param name="CanPlayerMove">If set to <c>true</c> can player move.</param>
	public void SetCanMove(bool CanPlayerMove)
	{
		m_CanMove = CanPlayerMove;
	}
}