Ben: Thanks for the reply. The source & binaries (suitable for SD card loading) for "TinySNAKE" & "TinySimon" (no title screen video yet for either, but they do still show up in the initial menu system) can be found in their respective folders under the "PocketArcade projects" folder in my Google drive at the following URL:
https://drive.google.com/open?id=1Pv0LDGhe3uLNJvhF7-aSdTOSZMYe8hbxBoth of these play a quick "charge" sound at startup, & have additional sounds in the game. All of these sounds are simply calls to tone() / delay() / noTone() & should easily show the reported symptom. It does seem that if the PocketArcade has been off for some time, the volume is usually louder, but not always. However, as soon as power is cycled, that's when the volume is definitely decreased & becomes inconsistent.
Let me know if you need anything else & thanks again !!
Mark J Culross
KD5RXT