The A-Engine: A new Beat 'em Up game engine

[A-Man]

But these aesthetics would compensate, don't you think? Plus, I find it rather innovative to have as little UI as possible.
There has been a lot of drama in the anime about the ship being the natural home of pirates, and a symbol of freedom in general. The author has provided the ship with great detail, to the extent that he drew "blue prints" for it, and it would be a loss to not have the ship in somehow in the game as well. I myself really like the idea of having the game start with you controlling a player on board of the ship, allowing exploration of all the different rooms in it with animated NPCs and all. It also allows for a great deal of easter eggs, minigames, and these small details people are fond of.
http://fc00.deviantart.net/fs71/f/2014/2...7shrpn.jpg