_init() function is called by Pico-8 to initialize a cartridge.
You define this function in your game's source code. It takes no arguments.
Pico-8 calls this function after evaluating all of the source code. In typical usage, a cartridge's source code includes definitions for functions and variables, an
_init() function, and
_draw() functions for the game loop. Pico-8 calls
_init() once before starting the game loop.
If any code outside of functions has side effects, these effects occur before
_init() is called. (This is trivial if the code consists only of function and global variable definitions.)