should be fine, games used come with instructions or manuals, just put the instructions on the itch.io page
Jeana said it right. :) Yes, you can use an external .txt file or the itch.io page for instructions and the like.
I drew each letter to show dialogs in game, but realized a bit late that I can't really fit that many letters on the screen...
But oh well, just rolled with it. ;-P I just can't use any long words.