To try out the game, you need to download the .swiftpm file. DISCLAIMER: You must have either xCode on macOS or Swift Playground on an iPad, so rename the .swiftpm file to .zip and extract it. Then go to Swift Playground and click “New Playground” and click “App,” then add the files by clicking “Insert from...” Then take the extracted files, which should have the .swift extension, and click on the files with that extension.