There seems to be a bug with the keyboard controls. You can use the Tab key to get past the Main menu. Gamepad Controls should work as normal.
Viewing post in Nova's Adventure (Sage 2024 Demo) comments
If you have a PC-compatible controller, you could download JoyToKey, and open that program. Then, start pressing buttons on the controller, and you'll see slots of the JoyToKey window turn yellow. If you type a keyboard key into that slot, the controller will then be able to type that key.
Here's a download link:
https://www.mediafire.com/file/xlfhi2o02z2enxg/JoyToKey.zip/file