It's Contra crossed with Metal Slug and that's all I need to know.
Tribute Games has confirmed over at the PlayStation Blog that Mercenary Kings will arrive on the PlayStation 4 on April 1. Yeah, you can consider it an April Fool's joke if you want.
Choose between Empress and King, two members of an elite squad known as the Mercenary Kings. Then, explore Mandragora Island with the ultimate goal of rescuing Dr. James Neil from the forces of C.L.A.W. (Cyber Loyal Active Weapons). If you fail, the evil organization will use Neil's secret Mandrake Formula to rule the world. You can either take on the noble quest yourself, or you can team up; as many as four players can participate, via local or online multiplayer.
The materials you gather during your adventure can be forged into powerful cannons or sharp blades, and there are over 300 gun parts and 100+ knives! Ever heard of a side-scrolling action game with such a deep customization option? Well, now you have.
Related Game(s): Mercenary Kings