In main menu:

F2 = enter level editor

In game:

Ctrl+E = edit current level
R = restart game
F3 = load game
Left = left
Right = right
Up = jump
Down = action
Esc = return to main menu

And in level editor:

F2 = save game
F4 = swap player and shadow's pos
F12 = suicide
Ctrl+N = new level
Ctrl+O = open file
Ctrl+S = save file
Esc = editor menu
Enter = edit properties of object under mouse cursor