This game is better then the original. Although essentially the gameplay is the same, there are some new additions, involving the other characters in your team showing up and doing a musou attack with you, and other new little gimmicks, like "Strategies", achieve a certain goal and your character says something and there is a morale boost or your allies are healed.
There are 92 characters, all the new characters from Samurai Warriors 2 Xtreme Legends, Yoshimoto having his new character model and moveset, and some 9 new characters. Nu Wa and Fu Xi from DW3 return, with new models, and Taigong Wong, Kiyomori Taira and others, including Himiko, who was seen in Kessen 2 but not since all add new villians and allies to the story, and further dive into the world Orochi created.
You can also play through a prequel to the first game, Orochi's story, which shows his arrival and how he got many people on his side, weather they wished to or were forced to join him.
There are more game modes. VS Mode comes back, with tag team which is like a fighting game,with the gameplay changed to fit it, you can even ring your enemies out! Dream Mode is also in the game, where you play through stages with a preset team, where they all have a role and a unique part of the level.
Music from past games return "Eve" from DW4 is just one of the fantastic songs returning, most are in Dream Mode, but the song changes during levels, so there is lots of cool music.
Basically, if you love the Warriors Series, GET THE GAME! If you loved Warriors Orochi, GET THE GAME! It is better the the original, but still keeps the basic elements from it strong.