Use (https://p8png-to-p8-hexadecimal-string.geotale.repl.co/) to convert a .p8.png file to the .p8 file as a hexadecimal string. If you have a plain .p8 file simply convert it to hexadecimal with the one site and enter it into this
Matt Thorson and Noel Berry for the example game (Celeste [Classic], not licensed) I would link to the original game but the site has a forum :( See inside for some more info about what this does Any tips on how to create a Lua interpreter? These aren't stored in ROMs but rather in Lua...