Fight your way through hundreds of baddies (and evil eagles) to rescue the princess.
Game description:

High atop a craggy cliff, guarded by an army of fierce warriors stands the fortress of the evil warlord Akuma. Deep in the darkest dungeon of the castle Akuma gloats over his lovely captive, the princess Mariko.
You are one trained in the way of karate: a Karateka. Alone and unarmed, you must defeat Akuma rescue the beautiful Mariko.

Put fear and self-concern behind you. Focus your will on your objective, accepting death as a possibility. This is the way of the Karateka.