I don't even think there was a full screen bug, it was probably just something to do with the timing being off when I ran the project. -- This is a demo. -- Not everyone in the studio was included in the credits, for either they weren't on the jobs list, or I could not find that many Sonic Dungeons projects on their profile.
=========================================== Sonic Dungeons Official Studio: https://scratch.mit.edu/studios/30081789/ ===========================================