If I said the words “underwater side-scroller,” I wouldn't blame you for recoiling in horror, having flashbacks of the horrendous underwater levels of every 2D platformer you've ever played, and lying on the floor whimpering in the foetal position for several minutes. Well, fear not, because this game is not a platformer, and you don't swim like you're weighed down by concrete boots.

Aquaria is a 2D, underwater exploration game in which you play as Naija, a pale-green humanoid creature with webbed feet, hands, and... ears? OK, that just seems like an evolutionary hiccup; those are going to do nothing but create drag, but then I'm not a fantasy marine biologist.

Aquaria puts more emphasis on adventure than action (which I'll get to later). The game world is massive, but you get a map of each area as you discover it. It's as much fun to explore methodically as it is to just forget about the map and wander aimlessly, taking in the view. The visuals are beautiful, even now, six years later; it's like exploring a giant painting, with an amazingly wide variety of creatures, from the gorgeous to the downright creepy. The world really is stunning; it could be a bit more detailed if done today, but this wouldn't add a whole lot.

The story kicks off with Naija telling us how she was perfectly happy with her simple life in her little alcove, but all that changes when a shady creature with a glowing, blue, smoky face comes to her one day and touches Naija's face, giving her a nightmarish vision. She gets restless after the hallucin– er, vision ends, and goes a wandering, encountering dangerous creatures, and, shortly after, gaining the ability to blast them into fish goo.

There isn't much to the story, but the few brief bits of narration are done rather well. ...er, except for the few times it gets a bit cliche, but even then, it's well acted. Actually, the story seems a bit lacking; it does the job of giving the world some coherence, but it's more of a narrative duct tape than an actual story. There's the start of a half-decent story, but nothing is ever fleshed out. Naija seems a bit out of place in this world, being the only sentient creature with more than just a simple survival instinct. You meet a human about halfway through the game, but they add about as much to the story as the wildlife. So, in summary, the game keeps you from wondering “what in the ocean am I doing?”, but don't play this game expecting a great and enthralling story.

The very end is a bit frustrating — or rather the secret ending that you only get if you find all the secrets, which I'm not going to tell you about because it's secret. The creators chose to make it a cliffhanger, but then never made a sequel. Hinting at a sequel and never making one is one thing, but displaying “TO BE CONTINUED...” in big letters across the screen right before cutting to the credits is about as close to promising a sequel as you can get without explicitly saying there is going to be a sequel. If, however, you don't find all the secrets, and don't get the secret ending, the story is wrapped up moderately well. A secret ending should be better than the other ending(s), and I really hope the writers learned from this screw-up. With that said, the final level, and the build up to the final boss fight is done really well; it's just the wrap-up after the climax that is unsatisfying.

Now for the action part: I'd be lying if I said that the combat takes a back seat to the exploration, but neither does the gameplay revolve around combat; the combat complements the exploration. Your primary attack (acquired very early in the game) is simply “shoot,” and “hold left mouse-button to charge up three simultaneous shots,” and the other attacks you acquire throughout the game are just as simple. The challenge is more in dodging attacks than aiming and planning your own attacks, and, unlike most action games, knowing when to just get the hell outta dodge. Even when you're not overwhelmed with a swarm of powerful enemies, it's often easier to just keep swimming past, especially if you're just passing on the way to somewhere else, and they're quite slow; and if you're only being attacked with projectiles, just activate the shield and swim away.

The controls can be a bit awkward at times. The game is meant to be playable with only the mouse, but I often had to resort to the keyboard for movement when I wanted to flee from an enemy in one direction while shooting at it in the other, and because the levels are very curvy and not boxy, an analogue control (i.e. the mouse) is really essential. You'll also want to use the number row on the keyboard for switching between forms when under pressure, because it's much faster than singing. Even with the mouse, the rapid right-clicking to blast away large swarms of enemies was starting to make my middle finger twinge after less than an hour. The game also supports using a gamepad, but the developers didn't bother to come up with a decent control scheme, so all you can do is map buttons like keys. At the very least, let me use the right stick for projectile aiming, instead of hard-coding the mapping to “look.”

You also don't get any upgrades, only new abilities, and the occasional pet, which floats around you and attacks random enemies at a very slow rate, never taking any damage themselves. They're actually pretty useless, and are even a frustrating distraction when you're fighting enemies of the same species. You see, the pets are acquired by killing minibosses and stealing their eggs, which hatch immediately, and the orphaned offspring imprints on you and will attack anything that looks at you funny, but at a ridiculously slow pace. The only visual distinction between your pet and an enemy of the same kind is their size: your pet, being a youngun', is slightly smaller, but when surrounded by a pack of kamikaze nautiluses or lazerball-belching turtles, your midget clone doesn't exactly stand out from the crowd, so you may find yourself trying to shoot down your invulnerable ally, or mistaking a hostile for your pet, and wondering why you're losing health.

Although there are no upgrades, you can get temporary bonuses from food, which you can cook or find. Harvesting some of the ingredients can be a bit of a grind, but you mostly won't need to stock up except in preparation for boss fights. The lack of upgrades suits the game quite well, actually, as the game is more about exploring than fighting. In a game where you can run away from tough enemies, an upgrade system would be a bit misplaced. It would be like giving Gordon Freeman, the one-man tank, a “run silent” upgrade.

All in all, Aquaria has aged well and is still an amazing game, with some of the best character and level design, especially the bosses. Still waiting for the sequel, by the way, guys.