Headless runs and screenshots

gasm-run can run the game without a window, with scripted pad input, and write the last frame as a PNG:

gasm-run build-gasm/openballance.wasm --rom Ballance.iso --headless 2072 --no-hash \
  --input "1000-1005:A,1150-1155:A,1750-1755:Y,1900-2400:DOWN" --screenshot level1.png

--input takes frame ranges with buttons (A B X Y L R SELECT START UP DOWN LEFT RIGHT). Useful moments:

Frame
~990	the main menu is up
1000 + Enter	the level selection
1150 + Enter	level 1 loads (press DOWN N−1 times before it, with --param unlockall=1, for level N)
~1750	the start prompt (Y = Q dismisses the tutorial)
~1930	the ball appears

The gallery's screenshots were made this way.