Let's add in an overlay to be displayed when GigaGal completes a level!
First we'll need to add a flag to the Level to indicate when GigaGal has reached the exit portal. Then we'll need to create a suitably awesome overlay to display. A congratulatory message plus a bunch of explosions (fireworks?) sounds good. Finally, we need to work out the logic of when and how long to display the overlay, and when to start a new level!
Check out the TODOs to get started.``````````