This game is amazing. I love the series, please read this review so hopefully you too will give it a try.
So, the story is a VERY basic one. Princess finds strange happenings in castle, writes a letter to the hero and your character Samonosuke for help, Samonosuke arrives too late and she mysteriously disappears, off you go to rescue her. Sure it's plain, but it's effective either way. The English v/o is terrible and out of sync with the characters, but the game offers an alternate original japanese voice cast if you wish.
The gameplay in warlords is pretty basic, you get a plain sword off the start, and square is your attack. You later find environmental weapons, and their magic attack is activated by triangle. There are some basic puzzles throughout the game, and the camera is fixed depending on where you go (a la resident evil style). The movement is controlled via directional buttons, which as difficult as it is to start with, you adapt to.
However, early on in the game you receive an oni gauntlet which allows you to use your environmental weapons and absorb the cowardly souls of your weak and foolish foes muahaha! Just kidding. "Why do you need souls of weak and cowardly foes?" you may be asking yourself. Well, you can enfuse those souls with your weapons, allowing you to break stronger door seals (seals that prevent you from entering certain areas) and making your weapons stronger.
The quirk in gameplay though is that you'll come to absolutely hate boss fights. You feel so weak when facing them, when you fell so powerful and bad*ss anywhere else. Most bosses will require multiple tries, and it's repetitive as you most bob and weave, hittin the boss twice then running away before he hits you and takes a huge chunk out of your health.
Overall an excellent game, I recommend the whole series (except Dawn of Dreams and the GBA one, those sucks Hojo's) so get the essentials pack and start the addiction!
Onimusha Warlords (the first one) Gets a 9.3 (9) out of 10.