Hi, I finished several run, defeated mewtwo, and get mew and missingno. Is there something else to do?
I have the feeling that something is missing but I don't understand... like the blue door upstairs, or the closed gym door on the cinnamon island.
I also defeat one time the man behind the door that say: "I feel...relived".
Sorry for spoiler lol
Upstairs, in the last door on the left, you can enter codes. Entering one will take you to Cinnamon Island, and there you can find Missingno. You can find the code by defeating a trainer that appears after talking to a lady, who tells you "Joe found a bug." If I remember the name correctly. It's random and it's not always there.