One Piece 2: Pirate King is a free browser game based on hot manga One Piece, published by JoyGames in 2015.
I would like to recommend you this game.
Hope you like it :)

Thanks.
Because I don't like having to wait for one chapter to be released at a time I haven't read any further than the first encounter with Caesar Clown (I think that's what he's called). I suspect this game to include major spoilers for me, so it isn't for me. :)