Everyone knows Metal Slug, one of the most beloved and most famous videogames series ever. But how many of you know about Gunforce 2 (aka GeoStorm)? You don't? Neither did I until I read an article about Irem's history at Hardcore Gaming 101:
As you can see, the creators of Metal Slug are also responsible for this unknown gem which was created before Metal Slug. And since the gameplay and graphics of both games are similar some fans refer to Gunforce 2 as Metal Slug Zero.
After I read this article I downloaded its rom for MAME and played it until I finished it. And boy, it was such an enjoyable run and gun game, one of the best I've ever played. And propably one of the most underrated arcade games I've ever seen (which it never got a console port).
If you're fans of Metal Slug (which means most of you) I recommend you Gunforce 2.