With over 15 years of Warriors games it feels like I should know a little bit about what makes a good one. First up at least in the case of games like this one that are based on anime should make good use of all the story arcs to recreate them in the style of a beat em up game. Which this game does well with plenty of cut-scenes to explain the story while also giving the game some over the top finishers once you beat a boss. Next up the player should be able to dodge attacks while also dishing out fury of attacks. Once again this game has that as well since it has a dodge move that can interrupt attacks while also letting the player bring out attacks when they are out of danger.
The 3rd thing that makes a Warrior game good is that it usually has a large cast of characters with unique animations that give them a semi unique move set even if it still just comes down to hitting square and triangle a lot. No surprise here but the fact that this is based on One Piece gives each character their own unique looking set of moves that must be figured out if you want to use them well on harder difficulties. Finally the forth pillar is the fact that the combat has a flow to it that you can keep riding till you finish each stage. And once again PW3 has that as well thanks to the fact it always keeps pushing you to the next objective till you finish a level.
This is what I think forms a good Warriors game but I'm not sure if they've managed to make a great one yet. Which is a lead on to a few issues I have with this one. The Dream mode in this game feels like it was put together by a random number generator. Each stage feels exactly the same with the only difference being that the set of characters you fight are different. Plus after a while you will notice that events are random and will be repeated many times over. Thus the repetitiveness of this mode could get tiring after a while. The leveling system also seems to be set up for you to grind a bunch which never seems that fun in most games.
In the end the well put together story mode makes this game worth experiencing if you like One Piece. Plus even though the dream mode is repetitive if you do enjoy the action of a Warriors game you could put in quite a few extra hours just challenging the many islands.
*Edit I just noticed I posted this as a PS Vita review by accident. Although it is still applicable to it this is a review of the PS4 version.