itch.io

Ah, that is possible with pan_game variables.

https://adventuron.io/docs/tut/#PersistantVariables

start_at                 = my_location
booleans {
   has_shown_intro : boolean "false" scope="pan_game";
}
on_startup {
   : if (has_shown_intro == false) {
      : print "This is a spooky game !!!!" ;
      : set_true "has_shown_intro" ;
      : press_any_key ;
   }
}
locations {
   my_location : location "You are in a room." ;
}