scripts/Player.cs

using System;
using Godot;

public partial class Player : Area2D, IHasScore
{
    [Export]
    private int moveSpeed = 200;
    public AudioStreamPlayer ScoreSound { get; set; }
    [Export]
    public Label ScoreDisplay { get; set; }
    public int Score { get; set; }

    public override void _Ready()
    {
        ScoreSound = GetNode<AudioStreamPlayer>("AudioStreamPlayer");
    }

    // Called every frame. 'delta' is the elapsed time since the previous frame.
    public override void _PhysicsProcess(double delta)
    {
        // Move up and down based on input.
        var input = Input.GetActionStrength("ui_down") - Input.GetActionStrength("ui_up");
        var position = Position; // Required so that we can modify position.y.
        position += new Vector2(0, (float)(input * moveSpeed * delta));
        position.Y = Mathf.Clamp(position.Y, 16, GetViewportRect().Size.Y - 16);
        Position = position;
    }
	
    private void OnAreaEntered(Area2D area)
    {
        if (area is Ball ball)
        {
            var direction = new Vector2(Vector2.Right.X, (float)Random.Shared.NextDouble() * 2 - 1).Normalized();
            ball.Bounce(direction);
        }
    }

}