Onimusha: Warlords has plenty of collectibles and secrets to find. Released originally on the PlayStation 2 this remastered is packed with collectibles to find, hidden weapons to acquire, and secret game modes to unlock, including Ultimate Difficulty.
Contrarily to its name, Ultimate Difficulty is actually the easiest in the game. In order to unlock it you must complete the twelve stages on Oni-Spirits. Upon completion, Ultimate Difficulty will be unlocked. The reason this difficulty is easy is that you get to start the game with the Bisimon Sword which kills almost everything in one hit.
Check out our Onimusha: Warlords walkthrough for more tips, how to find the best weapons and armor and much more.