Because I don't have save states with my Everdrive X3, I've decided to make a rom hack to be able to select any level when the game is started.

Looking around, I found some useful RAM address:

• 0x09C5 and 0x09C6 are flags for the completed levels
• 0x09C7 and 0x09C8 are flags for map progess (shortcut, color on levels, ...)
• 0x0086 flags for mickey power ups

Using Emulicious I could locate where things are initialized and checked in the code. Here are all the changes I've done for the rom hack without going into the technical details:

• let mickey walk anywhere and enter the level
• unlock all the progress so the map looks complete and no need to plant the magic bean
• give mickey all the power up and 3 stars
• allow to play the level again after beaten, some level plays a cutscene
• able to use the flute to skip the level any time

Updates! I've made a V2

• use the flute in boss room
• load the first part of the level 2 (lower water)
• don't loose life when dying
• remove animation to make things faster (overworld map, flute, death, ...)
• reset flags when starting level (chests, final door)