Do you want to be a super (voxel) hero?
In your PlayerScript class, you have two variables, runSpeed, and jumpForce, and you initialize them in Start, like this:


void Start () {
    runSpeed = 20;
    jumpForce = 10;
}



This isn't necessary. Rather, you can do something like this:

public class PlayerScript : MonoBehaviour {
    public int runSpeed = 20;
    public int jumpForce = 10;
}


This will also mean that the variables runSpeed and jumpForce will have the default values of 20 and 10 in the Unity Editor as well.

In addition, in your SphereTriggerScript class, you also don't need to initialize playerObject in Start as well.



In your SphereTriggerScript class, in the method OnTriggerEnter, you never do a check to make sure that the collider is actually the Player GameObject. In order to do this, you'll have to wrap the contents of SphereTriggerScript.OnTriggerEnter in this if statement:

if(other.gameObject.name == playerObject.name)
{
    ...
}


This ensures that in case any other GameObject happens to collide with a power-up, that it won't be destroyed.



The UnityEngine namespace comes with a static class Random, which I prefer over System.Random while using Unity3D. Rather than having to instantiate System.Random, I can just call the methods directly from UnityEngine.Random.

Compare:

System.Random random = new System.Random();
int randomNumber = random.Next(0, 100);


To:

int randomNumber = (int)Random.Range(0, 100);




Other than the above, I just have a few small nitpicks:


The general style for storing an instantiated GameObject is the below example, not containing the Gameobject. prefix, and using as for a cast instead.

GameObject gameObject = Instantiate( ... ) as GameObject;

In addition, C# braces should be placed on the next line, not like Java braces, as seen in the below example.

if( ... )
{
    ...
}

Finally, you have a few magic numbers scattered across your code, so here's a small list of places containing magic numbers:



  script.jumpForce += 1;


  script.runSpeed += 1;


  int randomNumber = random.Next(0, 100);


  int randomHeightOffset = random.Next(2, 12);




Other than that, your code looks pretty nice! I'm excited to see where this game goes!