Steel Diver (universe)

The Steel Diver universe refers to the  series' collection of stages and properties that hail from Nintendo's simulation, action games series in which the player controls a submarine via a set of touchscreen based levers and wheels. A relatively new Nintendo franchise with a very small fanbase, it managed to catch the attention of the developers, who incorporated a stage based on the eponymous submarine in Super Smash Flash 2.

Franchise description
At E3 2004,  was first shown as a playable tech demo for the then-upcoming Nintendo DS. The concept of a sub game, however, was, according to Shigeru Miyamoto "Long before that" and stems from Miyamoto's desire to make a flight sim. Even though he had created Pilotwings which has some similar aspects to the genre, Miyamoto was not fully satisfied with its simulation aspects. He noted that a true flight simulator players "should be flying a huge passenger aircraft instead of, say, a fighter jet". He also noted that a submarine was similarly big and bulky and thought that the subject might work for a simulation game. He had considered developing the game for a system before the Nintendo DS, but soon realized that the control system for such a game would be less than ideal. Even though the tech demo at E3 2004 had good buzz Miyamoto was unable to expand on the idea until late in the DS's life due to scheduling conflict. When a team was finally able to be allocated to the project the 3DS specifications became known to him at which point he felt the game would work better as a 3DS title.

Six years after the DS demo Nintendo revealed the game at E3 2010, as a launch title for the. The game was developed by Nintendo's Entertainment Analysis and Development division in cooperation with the external company Vitei. It was released in North America on March 27, 2011, where it was one of the first games for the Nintendo 3DS. However, it did not make the Japanese and European launch window. The game was released in Europe on May 6, 2011, and in Japan and Australia on May 12, 2011. It received mixed review from critics.

In June 2013, it was announced that Nintendo is working on their first free-to-play game, which would be based on Steel Diver, to be released by March 2014. This was ultimately revealed to be titled Steel Diver: Sub Wars during the Nintendo Direct on February 13, 2014, which released after the event for the Nintendo 3DS. Sub Wars is a first-person game featuring a free-to-play online multiplayer mode and two levels of the single player campaign, with additional features and missions available to the paid version. Reviews were mostly positive.

In Super Smash Flash 2
Steel Diver has gained some notoriety despite being a relatively new franchise by Nintendo. For now, one stage has been made available and features unusual physics.

Stage

 * Steel Diver: Taking place on the husk of the Steel Diver, this stage has the distinction of being completely submerged underwater, because of the that, characters tend to be floatier than usual and they descend considerably slower. Using the hazard switch disables this floatiness and makes gravity normal like any other stage.