Half-Minute Hero

An evil dark lord threatens the peace of the kingdom. He has cast a spell that will destroy the world in exactly 30 seconds, and an intrepid young hero is the only one who can defeat him. This hero has made a pact with the Time Goddess, protector of time, which allows him to level up extremely quickly and turn back time (for a nominal fee, naturally). He must defeat the dark lord before the spell can be completed...but of course, there's always another one waiting to take their place. Half-Minut...