To enable cheat codes, press I to pause the game, then type WINDY at the prompt.
ALT+F1: Gives all spells.
ALT+F2: Gives more mana.
ALT+F3: Kills all magicians.
ALT+F4: Destroys all hostile castles.
ALT+F5: Pop hostile balloons.
ALT+F6: Heals you.
ALT+F7: Kills all creatures.
ALT+F8: More spell experience points.
ALT+F9: Free spell usage toggle.
ALT+F10: Invincibility toggle.
SHIFT+C: Completes the current level.
SHIFT+D: Completes the current objective.