To enable the cheats, press i, type in windy and then press Enter.
Alt F1 - All spells
Alt F2 - Mana
Alt F3 - Destroys all players
Alt F4 - Destroys all castles
Alt F5 - Destroys all balloons
Alt F6 - Heal
Alt F7 - Kill all creatures
Alt F8 - Spell experience points
Alt F9 - Toggle free spell usage
Alt F10 - Toggle God mode
Shift C - Finish current level
Shift D - Finish current objective