How to prevent a 2D Kinematic asset passing through a 2D Box Collider.

I am creating a game inspired by Agar.io, and I'm having trouble stopping the player movement from exiting the game space.

This is a general idea of how the game looks right now, but I cannot solve for the life of me why the Kinematic ball under the camera, keeps passing through the Collider at the bottom.

![alt text][2]

Here's the script for the ball, written in Js.

==========

using UnityEngine; using System.Collections;

public class LoseCollider : MonoBehaviour {

 void OnCollisionEnter2D (Collision2D collision) {
     print ("Collision");
     }

}

==========

And here is the script for the Collider. Any help for this would be IMMENSELY appreciated. Thanks all :)