Arrow keys to move. 0 to ender/ exit editor mode. Keys 1-9 to change selected category. The same keys to change selected tile. Click to place/ delete tile. Get to the flag to win. Hit enemys at their head to kill them. Do not fall out off the world or run out of health. L to load a level. S to save a level. R to reset a level.
Thank you Griffpatch for your you-Tube tutorial. (I didn't follow your tutorial step by step.)
