A TwoPointFiveD [[AddedAlliterativeAppeal side-scrolling submarine simulator]] from Creator/{{Nintendo}} for the [[Nintendo3DS 3DS]]. You pilot one of three subs (an adorable little compact sub that can [[BoringButPractical fire torpedoes vertically]], a medium-sized submarine which is JackOfAllStats, and a [[CoolBoat four-torpedo-tube heavy sub]]) through a variety of stages, dodging depth charges, naval mines, and [[HotSubOnSubAction enemy submarines]] along the way. A gyroscope-enabled periscope minigame and a multiplayer turn-based strategy mode round out the package.

In 2014, a (mostly) free-to-play sequel, ''Steel Diver: Sub Wars'' was released. Unlike the first game's 2.5D presentation, ''Sub Wars'' is in full 3D with a first person view from the sub. The main focus is the game's surprisingly fun 4 vs. 4 multiplayer, which some have likened to ''VideoGame/AceCombat'', if ''Ace Combat'' was underwater and about submarines. It helps that the multiplayer (and the first two missions of the game's single player campaign) are free to download, with the rest of the single player and a few extra subs being unlocked for 10 dollars.
!!The following tropes appear in this game:
* BoringButPractical: Sure, the small sub only has one torpedo tube, no pitch wheel, [[ArsonMurderAndJaywalking and is painted a rather ugly color]], but as it turns out being able to fire straight up comes in handy.
* TheCameo: Peppy Hare from ''VideoGame/StarFox'' makes a cameo in ''Sub Wars'' when advertising the full version and it's features. Similar to the bunnies in ''VideoGame/StreetPassMiiPlaza''.
** A later update adds the Blue Marine from ''VideoGame/StarFox64''.
* EveryoneKnowsMorse: The only way to communicate in ''Sub Wars'' is through Morse code. Thankfully, there is a chart that tells you how to spell out each letter and messages are in regular letters. The single button chat system is, supposedly, more convenient than using the touch screen to type.
* ExcusePlot: [[ExtyYearsFromNow In the year 19XX]], a rogue nation threatens world peace. A coalition submarine force has been assembled to take them on. You're part of it.
* HotSubOnSubAction: Inevitable, really.
* TwoPointFiveD: Only it's in stereoscopic 3D, which makes it... 2.75D?
* VideoGame3DLeap: ''Sub Wars''.