A few weeks ago, Windows 10's lock screen suddenly served up an image of unearthly beauty: a luminous alien mushroom vehicle of some kind, delicate and almost translucent, perched on the end of a midnight jetty. It turned out to be the diving gondola at the end of Selin Pier in Germany, and I was so captured by the idea of the thing, the way in which its fantastical form enabled its fantastical function, that it was hard not to dream about a quick trip through the waves in it. Slope downwards to thy depths, O sea! There is a peculiar imaginative tug to the strange life that awaits at the bottom of the ocean. There is a horrible romance and adventure to the things that scuttle over the dark sands down there, things born without jaws, without eyes. This may explain why a game as traditional as Song of the Deep had, at times, a gentle hold on me that its individual elements do not quite justify. At times.
Not that tradition is ever a major mark against you in a metroidvania, the action-adventure genre built of back-tracking and gear-gating, puzzles and boss battles, that plays out across a single complex environment. The template is strong to start with here, and it's only reinforced with every new example. Song of the Deep is not a bad metroidvania by any metric. Its storyline is suitably sweet-natured, as a young girl leaps into a submarine to search the oceans for the missing father who has told her so many wild tales of his life as a fisherman. Its 2D visuals are pretty enough, as your golden craft chugs through the swaying depths, its passage triggering bioluminescent fronds on nearby plants, while the scenery changes from shipwreck graveyard to submerged city, shattered finials replacing rusting figureheads. The weapons and gadgets you're given are suitably potent, most notably the grappling hook that allows you to pick up and throw rocks and shells, but which also doubles more directly as a ranged weapon with a nice thud to it. And the enemies were never going to disappoint: electrical jellies swarming and multiplying, armoured crabs with hidden weak spots, splay-toothed anglerfish - a fish so monstrously unlovable that it looks like it came from D&D's Monster Manual in the first place. (It isn't in there, I've checked.)
And yet, Song of the Deep pays a price for this warm embrace of genre. This isn't a bad metroidvania, but it is also far from being one of the best, and if you've played any recent metroidvanias, let alone an undersea offering like Aquaria, you're not going to see much that you did not expect in here. And yes, some of this is because the genre demands it. There's the progression by means of different doors and keys, of course: jellyfish who block vital gaps and only flee once you have headlamps to chase them, stone walls that crumble beneath a rocket impact, fire barriers, ice barriers, glass barriers, all of which have their counter in your steadily improving arsenal. There are the upgrades, which allow you to boost a little further against the strong tide, to turn a missile into a shield or a mine, or to alter the health drop-rate of defeated foes. All of these things are fine and most of them are entirely necessary - but none of them are handled in a particularly exciting manner, and the best metroidvanias make their familiar components exciting with inventive twists.
This slowly starts to feed into the journey itself, as you wiggle your way through a sea that has been turned, for far too much of the adventure, into a series of pokey corridors and small combat arenas. Bosses are surprisingly thin on the ground, and they're a little lacking in imagination in terms of visual and mechanical design. The big-ticket items, such as the ability that allows you to get out of the craft and explore small gaps in the scenery, never really turn up any moments that dazzle, either. The beats of the story are quietly affecting, but the set-pieces are nothing you haven't played through a hundred times before. Chase sequence? Got it. Unkillable foe section? Ditto. Light-beam mirror puzzles? You bet.
Those light puzzles are interesting, actually, because they mark the one point that Song of the Deep, which is an Insomniac game, actually feels like it's come from the studio behind Ratchet and Clank and Sunset Overdrive. There isn't much that's fresh or daring to a sequence that has you splitting spectrums of light, bouncing rays off reflectors and into switches to trigger doors, but the way it's arranged here is utterly mesmerising regardless. You're inside a single huge structure, working your way up through the mass of it. For the last hour or so you've heard about this ancient place, so the build-up is taken care of, and the final reward is a delight too: just enough brain-teasing, just enough spectacle, just enough of a twist - heavily signposted - at the conclusion. This is Insomniac, the master of details, of pacing, of pay-off. It's the stand-out sequence in a game that really needs two or three of them, but which lapses too easily into being a servant to tradition, delivering again and again exactly what's expected.
So - while your weapons are fun enough (I do like the intelligent lock-on to the elementally-flavoured missiles you pick up along the way), the secret areas are fun enough (although they generally just grant a few coins to spend at the ho-hum upgrade shop), the physics stuff is fun enough in its fiddly way as you grasp things and fling them, and the ever-pleasing act of filling up the map until there is no space that's unaccounted for is fun enough - taken together, Song of the Deep struggles to stand out, even given the design smarts of Insomniac and the towering brand presence of the sea itself. The best metroidvanias of the last 10 years all have something specific they excel at: the art of Guacamelee, the song system of Aquaria, that amazing foam gun in Shadow Complex. It's the unchanging structure of the genre - all those doors and keys - that actually forces designers to bring real creativity to the detailing.
Song of the Deep is clever, but it isn't that creative. It's merely rather good at covering its bases. I had a nice time down there, but I'm not sure I'll remember it. It's not the Selin Pier, after all. It's not that spectral gondola.