Steel Diver's best mode is also its most short-lived. Upon completing each mission, speed trials are unlocked. Punchier and more inviting than their lengthier counterparts in the main quest, these bite-sized maps task you with getting through hazardous – albeit enemy-free – terrain under strict time pressure (between 80 seconds and two minutes). Without the presence of pesky projectiles, you can be more daring in your manoeuvres. Unfortunately, there are only eight stages and only the last few provide any substantial challenge. As soon as it hits its stride, it comes to an end.
That encapsulates Steel Diver as a whole. What's there is good, but there simply isn't enough of it. There are only seven levels in the campaign, and the latter two are unlocked by beating every prior level with all three subs. The different subs are a great way to add variety, but requiring players to negotiate each level thrice only draws attention how thin the package is.
An unlockable expert mode is more exciting than the main campaign, and the option to race against the developer's "ghost" runs gives extra incentive to replay stages, but by that point you'll have seen each map so many times it will be hard not to crave at least a few new levels. There's also a turn-based multiplayer mode, but it's not much more than a variation of Battleship that requires too much guesswork and isn't particularly memorable.
This anaemic nature extends to the visuals. After watching Disney's Oceans and playing Nintendo's Endless Ocean, I've become entranced by the beauty and mystery oozing through our planet's subaquatic terrain. Steel Diver hints at this, with schools of fish, a couple of whales and an underwater volcano, but it stops short of truly immersing us in the the ocean's grim majesty. Environments are brightly lit and it rarely feels like you're more than a snorkel's depth from the surface.
While I appreciate Steel Diver's languid controls, there are times when they're simply not up to task. Homing torpedoes can be warded off, but regular projectiles and air-raid bombs occasionally appear too late to dodge. You also can't turn around. Moving in reverse usually gets the job done, but this would really come in handy during the game's few boss battles.
In spite of its steep learning curve, dearth of content, and lack of depth (both figuratively and literally), Steel Diver grew on me. It may have less to do with being a submarine commander than Trauma Center does with being a doctor, but it's a novel premise nonetheless, and the tactile fidgeting with the sub's controls is strangely rewarding. It's hard to shake the feeling that it was rushed out of port and its deliberate pace won't be for everyone, but those looking for something different might find Nintendo's nautical adventure a promising maiden voyage.
6 / 10