I think the first Onimusha was in development for almost 3 yrs? Whatever the time, was it worth the wait? Yes, yes, yes!
The important thing is how well the game was put together. An important distinction: Resident Evil was- survival/horror, and Onimusha was- Fantasy/action. This difference describes so much. Unlike RE where you run away from baddies to conserve your bullets, Onimusha encourages and often times forces you to face the enemy blade in hand. It's action oriented with very inventive puzzle elements.