Apologies for the delay in replying to this!
This error is not caused by the script itself, rather Unity does not know it is part of the project.
The best way to resolve this is to recreate your script from within the Unity Editor. We have not added any code at this point, so this should be painless!
- Open your Jetpack Joyride project in Unity.
- Delete your existing MouseController script.
- In the Project View, navigate to your Scripts folder.
- Click the Create dropdown on the top left of the Project View.
- Select C# Script.
- Immediately rename the new script MouseController.
- Drag the script over your mouse in the Hierarchy.
I hope this helps.
Any further problems give me a shout!