Gunster: Rain of Bullets

Gunster: Rain of Bullets (Gunstrike R: Reloaded Bullets in Japanese) is a 2D side-scrolling online shooter (more specifically a run & gun) created by Korean based company NHN USA Inc. who hosts the game via their regional portals (Ijji and Hangame). Originally the game was available for both Japanese and North American players, however the North American version was eventually shutdown on February 14, 2007 (due to development challenges).

Hangame, the original creator, once hosted the game for Korean speaking gamers but has since died off as well. The Japanese version, however, lives on.

Note that the game uses anti-hack software (nProtect), which must be installed and allowed to run. Like many other games with this sort of protection, doing anything outside of the game that might trigger the software to think that you might be trying to affect the game will cause it to close abruptly.

Story
Players assume the role of futuristic mercenaries sent on various missions that make up the Challenge and Mission licenses. All missions may be played single-player, but many can also be played in groups of up to three. Most missions consist of traversing a level from left to right while destroying enemies. Over the course of gameplay, players obtain "medals" which allow them to progress from the beginner challenges to the multiplayer Battle modes, including Survival and Deathmatch.

Versions
The Japanese version of the game was ahead of the North American one in terms of released features. It also had minor changes like character stats and names.

The North American version was in closed beta from September 13th, 2006 to October 9th, 2006. After a brief period of downtime, the "Live Service" started on October 18th, 2006. During the time of its playability, there were several "events" that temporarily changed gameplay, visuals, and rewards. The events that happened for the NA version include Halloween, Thanksgiving, and Christmas.