Source: Wikipedia, "Gunstar_Heroes," available under the CC-BY-SA License.

"Gunstar Heroes (ガンスターヒーローズ, Gansutā Hīrōzu?) is a run and gun video game developed by Treasure and published by Sega. On February 23, 2006, Gunstar Heroes was released as part of the Gunstar Heroes: Treasure Box Collection for the PlayStation 2. It is also available on the Nintendo Wii's Virtual Console and in 2009 it was released on June 10th for Xbox Live Arcade and June 11th for PlayStation Network.
Gunstar Heroes is a side scrolling shooter. The player has four weapons to choose from, and they can be combined in various pairs to create a total of 14 unique weapons. In addition to the weapons, the player can engage enemies in close quarters combat. It is possible to grab and toss enemies, perform sliding and jumping attacks and a long-range skid. The main highlight of the game are its boss encounters, which often feature large enemies made up of multiple sprites allowing for fluid movement."