Resogun (stylized as RESOGUN) is a side-scrolling shoot 'em up game developed by Housemarque exclusively for PlayStation 4. It is a spiritual successor to Housemarque's previous shoot 'em up games, Super Stardust HD and Super Stardust Delta, and a PS4 launch title released on November 15, 2013 in North America and November 29, 2013 in Europe. A demo version of the game was playable at the Sony PlayStation booth at gamescom 2013 and at Eurogamer Expo in London.
Source: Wikipedia, "Resogun", available under the CC-BY-SA License.