To get this out of the way, do not touch the World Version. Just play the Japanese version. It looks better and plays a bit better.
Asides from that, it's a very charming albeit rough beat em up. It feels like Fist of the North Star meets Final Fight. I really love the look, IREM never fails on that front. I just wish the boss and enemies were a little more balanced. I feel any fan of Nazca or Beat Em Ups should play this.
Also those clone enemy's totally inspired the clones in Metal Slug 3.