PlaydateSDK-1.10.0 on Ubuntu linux, Simulator.
The documentation for Inside Playdate with C says "The update function should return a non-zero number to tell the system to update the display, or zero if update isn’t needed."
However if you do return 0 from your game's update function then the game pauses with
update failed: (null)
17:38:39: Update failed, simulator paused.
The documented behaviour would be preferable to me over the implemented behaviour.
Many thanks! Tim.