Thank you so much for the comment! I did my best to make it accessible, and I tested it using a screen reader, but since I'm not used to using a screen reader it was hard for me to tell how well it worked. If you find any parts that aren't accessible, please do comment here or email me (bugs@johnayliff.com).
When you installed the game it should have made a start menu shortcut in a start menu folder called Beyond the Chiron Gate, so that's the best way to run the game. If you want to run the .exe file directly, you should run the one in the BeyondTheChironGate folder, not inside the app-1.0.1 folder.
I'll add a volume slider to my list of things to do for a future update.