The demo shows how your PICO-8 games could add dynamicity to sound effects depending on what happens and the action involving your sprites, depending on their position, speed etc... not just use a few prefab sfx or playing several different sounds to give the impression they react to the action (e.g. a vehicle acceleration, spaceship thrust).
There are 8 examples (presets, select them with 🅾️ and ❎) of sounds and each shows a simple preview of some game action. To interact with preset previews you basically change the Pitch with ⬆️ and ⬇️ keys.
At the top you see the two bytes representing the note, their address in memory (it's sfx 1), the values in binary (help you understand how 'components' such as Pitch, WaveForm, Volume, Effect are stored in the bytes) and their corresponding decimal values.
You can use ⬅️➡️ to select a different component and edit its value.
At the moment it's 'just a demo' (although it took me more than 2 weeks, longer than a single game dev) and it still doesn't offer some basic functions to copy into your game to implement dynamic sounds. I'll update it as soon as I test more myself on an actual game.