Song of the Deep isn't your usual Insomniac fare. This is a 2D underwater Metroidvania, and a rather lovely one at that. It has none of the bravado of the studio's most well-known output. Song of the Deep doesn't have a wisecracking arsehole protagonist, it doesn't feature an alien threat that is attempting to take over the world, it isn't about one of the most famous superheroes ever created. By taking a more whimsical approach to storytelling, this is perhaps the studio's most appealing game since Spyro the Dragon... until things take a turn for the worse.
This is a tale of a young girl who loses her father. After years of stories about what he saw on his adventures under the sea, one day the girl wakes to find her dad is gone. He's lost somewhere in the vast blue world, and with the help of a neat mini-sub and a variety of expanding weapons and tools, she (you) sets off to try and find him.
As is the way with Metroidvanias, the world you find yourself in is a mass of interconnected tunnels and caves, with areas out of reach until you have the ability required to reach them (a rocket to blow through barriers is just one of the additions that open up new areas). As you zip about the water you'll face enemies big and small in the form of various sea creatures. Initially you can attack them with your claw arm, a multi-purpose tool that also doubles as a way to ferry items around (perhaps a mine that can be moved to detonate next to an impassable barrier), but the aforementioned rocket launcher comes into play later on.
Defeat enemies or find treasure and you'll earn coins, which in turn can be traded for upgrades to whichever tools you currently have. One of these is the boost, which is essential to propel your sub through back-currents, with upgrades giving you more boost time and the required ability to, you guessed it, reach previously unreachable areas.
Song of the Deep nicely balances combat and exploration, with the game rarely feeling frustrating. Boss encounters scale up your foes, but these too are simply a case of learning what the required technique is and then executing it. At no point will you encounter combat difficulty spikes like those in Xbox and PC Metroidvania, Ori and the Blind Forest. You don't get the same heart pounding moments of exhilaration here, and generally Song of the Deep is a more laid back experience. Insomniac's game doesn't feature any platforming (it's an undersea adventure), but it shares a similar ethereal aesthetic to Ori, and also kindles a constant desire in the player to explore. It's gorgeous and benefits from a perfectly pitched soundtrack befitting of a deep sea fairytale.
That all sounds pretty good, right? It is. And then it introduces puzzles. Up until this point the game had switches and levers that had to be used in order to open doors, and the odd mildly tricky mine transportation sequence, but there was nothing too strenuous. About halfway through Song of the Deep, Insomniac introduces some truly maddening puzzles. These are perfectly solvable in terms of figuring out what to do, but the reliance on using the understandably floaty underwater controls to move things, or direct beams of light, makes actually doing the thing you know you have to do incredibly frustrating at times.
This shift in terms of gameplay is a real shame, as it slightly spoils what is otherwise an excellently put together Metroidvania. The level of annoyance brought about by the game's latter-half puzzles will vary, and there's still a really solid game around it, but Song of the Deep at times feels like it's singing from two different hymn sheets.