You can make PinballY play a custom audio and/or video file whenever the program starts up. Setting up the startup items is just a matter of creating suitable files in the Media folder within your main PinballY program folder.
Custom startup video: Place a file called Startup Video.mp4 in the PinballY Media folder. It has to use that exact name, including the space, but you can change the suffix from .mp4 to any of the other supported video format extensions (.mpg, .f4v, .mkv, .wmv, .m4v, .avi). If a file with this name (using any of the supported extensions) exists, PinballY will automatically play it in the main playfield window each time the program starts.
Custom startup audio: Place a file called Startup Audio.mp3 in the PinballY Media folder. Use that exact name, including the space, but you can change the suffix from .mp3 to .wav or .ogg if you wish to use one of those formats. As with the startup video, the program will automatically play back this file each time you start a new session.
If the startup audio and startup video files are both present, PinballY will simply play them both at the same time. It's best to use a silent video in this case so that the soundtracks aren't trying to shout each other down.