They could play Wolfenstein and Doom…
There are tons of HackerNews apps now.
Hack, Harmonic, and Trilby are my favorites.
Sync is amazing. Not FOSS, but amazing nonetheless!
There is a road, no simple highway
Between the dawn and the dark of night
And if you go, no one may follow
That path is for your steps alone
Ripple in still water
When there is no pebble tossed
Nor wind to blow
You who choose to lead must follow
But if you fall you fall alone
If you should stand then who’s to guide you?
If I knew the way I would take you home
Little Bubby Child!
The link suggests you still have to purchase Guitar Pro though