“Princess of Persia” game concept

I came up with a game concept today. Please tell me if it sucks, has already been done, or if perhaps it would be worthwhile trying to implement. — Young woman locked in tower uses the distractions of a prince’s bumbling rescue attempts to sneak out of her luxury tower prison room and mount her escape down the many levels of the tower.

On reaching her freedom she hops on the prince’s abandoned stallion and finds herself with a decision to make. Does she ride off to her freedom, or try to rescue the vast number of princes who have been incarcerated in the cellar dungeons after failing to rescue her? (Yay, extra levels!)