Before you can playtest the game, you have one last step to do. Click on File and go to Build Settings. You need to add all four of the scenes to the scenes in the Build section. To do this, select all of the scenes we are using and drag them into the empty section. It will look like this now:

Now you can build out an executable and play the game! When building on a PC, you'll get an exe file along with a data folder; on a Mac, you'll get an app bundle. The game will start from the main menu, then you will have to play the rest of the levels to return to the main menu and beat the game.