Arrow Keys Only. Press 1 key to show Tile Size controls and 2 to hide it. Has a lot of glitches, just be patient and it'll work (may need to press the green flag multiple times). Sometimes the maze might automatically regenerate again if the marker is placed in a bad place. If you want a quick generation, turn on turbo mode. (Shift + Green Flag)
Thanks to @griffpatch_tutor tutorial on youtube for help. Check him out!
