Just announced and released during the community direct, Goodnight Universe is a micro audio game to fall asleep with about the heat death of the universe.
I've had this idea in my head since before the Playdate, but the lack of front or backlight on the console really makes it make sense as it can be played in the dark with no screen light causing a disturbance.
I was also inspired by Pulp's noise channel to add an extra feature where the game's title screen continually generates low volume noise, meaning it can double up as a passive sleep aid. It was fun to work out how to poke the pulp music editor in the right way to do that!
The game's trailer was created in Pulp and can be watched in-game by entering the Konami code on the title screen. I really can't resist including cheat codes in my games!
This is definitely on the more experimental and conceptual end of the scale but I think Playdate really encourages that kind of thing.