Better controller for a 2d game

Unity Engine
1

I’m new to unity and I am trying to make a platformer. I have a controller but it is very odd and the jumping is all wack can someone please help change my code to make it better?

here is my code:

using UnityEngine;
using System.Collections;

public class AlienController : MonoBehaviour
{
    public float maxSpeed = 10f;
    public float jumpForce = 700f;
    Rigidbody2D rb;

    bool grounded = false;
    public Transform groundCheck;
    float groundRadius = 0.2f;
    public LayerMask whatIsGround;

    // Use this for initialization
    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    // Update is called once per frame
    void FixedUpdate()
    {
        grounded = Physics2D.OverlapCircle(groundCheck.position, groundRadius, whatIsGround);
        Debug.Log(grounded);

        float move = Input.GetAxis("Horizontal");

       rb.velocity = new Vector2(move * maxSpeed, rb.velocity.y);
    }

    void Update()
    {
        if (grounded && Input.GetAxis("Jump") > 0)
        {
            rb.AddForce(new Vector2(0, jumpForce));
        }
    }
}
2

What’s wrong with it? Is your overlap circle call failing and preventing a jump at all? Is the jump working but sending the character up too high? What’s your gravity set at? Lots of things could be wrong.

Maybe you should use ForceMode.Impulse?