Game test modes

Run normally, Avanor plays as a game. A handful of command line options put it into other modes instead, and 'avanor --help' lists them all.

Demo mode
'avanor --demo' runs the world with no hero in it, so you can watch Beelzevile, the horned demon, in his dungeon. SPACE pauses the demo; M gives you the message history; ESC leaves it.

Test mode
'avanor --test' runs the world without a hero for as long as you let it, which is how bugs are shaken out and how the game is timed. Two keys are worth knowing while it runs: L writes every location's map into location.txt, and I writes every item in the world into items.txt, both in your Avanor directory. ESC ends the run.

God mode
'avanor --god', or 'avanor -g', is for testing a real game without fear of dying in the middle of it. Your hero gets a thousand extra hit points and power points, and when something finally does kill you, you are asked whether you would rather carry on.
It also gives you three keys the game does not otherwise have. '^F' lights the whole of the level you are standing in, walls, creatures and all, and pressing it again puts the dark back. What it shows you is not written down - turn it off and the level is as unexplored as it was before you looked.
'^W' jumps you anywhere on the level. Move the cursor with the direction keys and the map scrolls along under it, so you are not limited to the part of it you can see; space puts you where the cursor is, and z or ESC changes your mind and returns the view to where you were standing.
'^I' makes you unnoticeable. Nothing in the world can see you while it is on: creatures pay you no attention, nothing comes after you, and a monster that walks into you simply stops rather than lashing out at something it cannot see. It is for watching the world get on with itself - following a goblin raiding party about its business, or standing in a guardroom to see what the watch does when nobody is provoking them. Press it again to rejoin the world. Two things it does not do: you are still solid, so creatures walk around you rather than through you, and you can still attack - and a blow struck while unnoticed is not answered, because nothing knows where it came from.
None of the three costs you any time, and a jump does not spring whatever you land on.

Choosing the world
'avanor --seed N' builds the world from the number N instead of from the clock, so the same N always gives the same world. It works in every mode, including an ordinary game - useful for meeting the same dungeon twice.

Self-tests
Three further modes check the game against itself and print a PASS or FAIL rather than showing anything: '--test-save' builds a world, plays a hundred turns and saves it; '--test-load' restores what it wrote; '--test-cereal' round-trips a single location through the save format. They are meant for the build, not for play. They keep their own save file, avanor-test.svg.zst, and never touch the game you are playing.

The mode options exclude one another - ask for two and Avanor says so instead of guessing. 'avanor --version' prints the version and exits.