Go to Menu > Settings > Security and tick the box that says “Unknown Origins” or “Unknown Sources.”
Go to Menu > Settings.
Scroll all the way down to find “About phone” (or “About Tablet”).
Scroll down again and find the entry with the Build number.
Start tapping on the “Build number section”, Android will now pop up a message informing you that in x amount of clicks you will become a Developer. Keep tapping until the process is complete.
Download the .apk file to your mobile.
Locate the folder that contains it and click on the .apk file.
Click on Install.
Pedro Moniz (programming)
Ricardo Rodrigues (programming, level design)
Rita Ribeiro (art)
Sara Martins (programming, UI design/art)
Vasco Rodrigues (programming)
Thanks to GTavares for making the sounds!