From the NES heyday shoot 'em ups like Gradius, and moving through the console generations with various sequels, Nintendo players have seemingly often had a soft spot for the genre. Right up to the recent tide of Neo Geo classics released on the Switch, including Blazing Star and Alpha Mission II, the genre continues to be well represented; while these titles are good for scratching that nostalgic itch, the contemporary scene is rather strong. With the rise off download stores and smaller studios, the retro classics on the eShop have recently been joined by the likes of Sine Mora EX and Graceful Explosion Machine - each offering their own aesthetic and gameplay twists on one of the most straightforward of straight up (or left to right) genres. 

While the shmup's mantra is often 'go in one direction and shoot anything that moves', Thai developer Pixel Perfex's new title Earth Atlantis reminds us that there can be more beneath the surface. Although it never tries to shy away from its roots, Earth Atlantis is also an exploratory and even reflective experience at times, but more on that later. 

Somewhat reassuringly (considering the genre) the backstory is as brief as it is shallow - after a catastrophic global event at the turn of the century leaves 96% of the earth under water and inhabited by a wide range of aquatic beasts, it is up to you to choose a submarine and go about taking them out, one by one. The quick introduction allows players to get straight in and focus on the key elements and mechanics.

Going up, down, left or right at your own pace - and taking in the scenery at times - is a welcome change to the frantic pace autoscrollers in the genre are known for, and all round movement feels good. Use ZL or B to turn your ship around, and A or ZR  to shoot. There is only 'quest mode' open and one ship available from the outset, but new ships are available after fulfilling certain objectives - how to acquire them would spoil the surprise. Even so, the final number of vehicles available is low with no customisation options. 'Hunter mode' opens up after successfully completing the game - essentially a 'Rush mode' to kill all bosses on a single life as quickly as possible. There is also a visual log of the boss monsters you have defeated. 

The enemies range from relatively harmless minions that regularly drop weapon upgrades - adding firepower and eventually an extra direction to your ships arsenal - to tougher foes, while you can seek out barrels or crates to find homing missiles, bombs or a burst of electricity. The main antagonists of Earth Atlantis are 38 giant 'boss monsters'. Without spoiling too much, these range from a static biomechanical octopus and a raging, spinning armoured king prawn to more organic types, such as a squid or sea turtle - with many more besides.

The difficulty of these boss battles fluctuates a fair bit, with one taking us over a dozen attempts after a gritty and intense war of attrition; we'd then casually cruise past the next few bosses on the first attempt, only to once more get hopelessly obliterated with an almost instant kill attack from another. It seems like the developer has taken this on board, as a rapid patch increased item drops and weakened certain bosses. While the battles are tough, and sometimes frustratingly so, with persistence and patience slaying each beast is immensely satisfying. 

Changing course from the more traditional titles in the genre, the exploration elements of Earth Atlantis are well balanced, opening up new areas after defeating bosses, with  'bullet hell' tropes taking a bit of a back seat. That's not to say that things don't get hectic - weaving and dodging through waves of enemies feels great and is initially necessary when the one sub to choose from has limited range, but nonetheless is a tense and fulfilling experience due to decent manoeuvrability. The more low key moments are a good mix of open areas and maze like rock formations. The mini map can also be turned on or off with X for a 'pure' experience, as it shows boss and power up locations; this reviewer felt that, although useful, this map somewhat imposed on the overall presentation, so the option to disable it is welcome. 

Anyone who is reading this review after seeing screenshots or watching any footage has no doubt noticed a glaring omission - the visuals. The game has won Asian video game convention awards since its reveal, and it's easy to see why. The sepia toned, meticulous line drawing aesthetic is instantly striking, but look a little closer and you'll realise that there are a wealth of subtle details that make the game stand out. The glorious depth of field and parallax is simply stunning, as broken buildings, scaffolding, famous landmarks and narrow caverns make up the one vast, semi-metroidvania style world. Whether it's noticing a majestic and docile beast swimming peacefully in the distance posing no threat, or navigating the abandoned structures in tighter areas, the visuals in both handheld and especially docked - as the game felt slightly faster and smoother on the TV - are a delight. Animations are fluid, and the game shows no slowdown during more intense moments. 

Despite the soundtrack being hand picked from licensed music, the boss battle tracks in particular are suitably orchestrated, brutal and epic, akin to something from Shadow of the Colossus. Disappointingly there's only a single overworld track, but it's appropriately ambient with a light sprinkling of more modern electronica sound effects. 

Conclusion

Even if you're not a 2D 'shmup' veteran, or are looking for something a little off the beaten, sidescrolling track, there is plenty to enjoy here - we have tight controls, plenty of unique monstrous bosses to defeat and exploration of a broken but beautiful submerged world. While it lacks a few options, has occasional boss fight difficulty spikes and is not the relentless action that some genre fans prefer, Earth Atlantis has enough old school shoot 'em up substance to back up its glorious and organic style.