Bit Blot's 2D side-scrolling adventure game Aquaria [$4.99] for the iPad is a gorgeous and well-produced title with a sharp emphasis on world-building and character growth. It's good, and I think the reason why it strikes me as such a quality download has more to do with its atmospheric allure than anything else. Aquaria begs you to explore with every ounce of its being by consistently introducing mechanical novelties, alien setpieces, fascinating creatures, and drip-feeding a not-quite-but-totally convoluted story that keeps you thinking that you're on the precipice of figuring out what's going on with your mercreature in the game's beautiful underwater world.

Most of the missteps in Aquaria are tied to the limitations of its new platform. Indie developer Bit Blot and its partners have masterfully replaced the cursor with finger, allowing for complete character movement without virtual pads. Strikingly, the shooting and "singing" components require virtual buttons. When these actions are coupled with the need to move fast, you�inadvertently�start playing Finger Twister instead of Aquaria.

For the most part, control isn't a huge problem. Aquaria's world has its share of danger and the occasional boss fight, but�as a whole it's more of an ambient, leisurely experience that's more centered on exploration of its lovingly crafted environments. It is somewhat telling where the priorities reside, actually, just by how routine the fighting parts tend to feel.

The art in Aquaria, in particular, is captivating and subtle. Bit Blot doesn't beat you over the head with concentrated "look at me" moves pointing out the ridiculous level of hand-drawn detail and quality present it both it, and for that matter, the marvelous sound and music production. On the other hand, the writing is pretty over-the-top.

Song is a bit part of the experience. You play as a mercreature who, one day, begins a quest to uncover the past of this world. Your 'weapon,' initially, is music that can conjure various abilities, including shielding as well as the ability to lift heavy objects or turn your mercreature into a fire-slinging demon.

You pick the notes to songs that summon these powers, kinda like how you played the ocarina in Ocarina of Time. The core difference is the visual representation of the notes, all of which seem to have a connection a specific element. Puzzles all subtely require a knowledge of what's at your disposal and often challenge you to think about combinations or around what you have. Environments usually lay down a heaping of clues, which helps and doesn't necessarily rob you of grand "a-ha!" moments.

If it helps, think of Aquaria as a pretentious Metroid-vania based in a fantastic sea. It adapts and adheres to a lot of those tropes, actually, so much so that it's pacing�can take massive dives. Want to explore over here? Nope, you can't because there's a big rock and you need to go over here first in order to learn the song to move it. Oh, you don't know where to go? Check your map. See that area over there that you didn't get to earlier? There's probably something over there you can open with a power you uncovered in order to earn something else to uncover another location or item. To be clear, this game delivers on all your wants from a Metroid-vania -- I might not be the biggest fan, but that doesn't mean you can't be.

Its gating and, as a consequence, your laser-honed desire to move past those barriers obscures some of the finer elements of Aquaria. Like, the cooking system, which allows you to take bits of "loot" or food you recover from enemies or plants in the world and morph them into something that boosts the stats of your character. On the other hand, these more subtle elements are what makes Aquaria so entertaining; it doesn't spoon feed you or tell you necessarily what you can do. It just lets you exist in its world.

Aquaria is refreshing. It's one of the handful of games on the App Store that you could call "complex" and entertaining in the same sentence while not subsequently pointing out an elaborate and infinitely tweakable RPG sub-menu or sub-system that has a hand in all the on-screen action. Not only is it beautiful, but it's engaging in its own way and has a host of things to find, explore, and be challenged by. Go grab it, already.

Ed. Note: Images in this review are from the PC version, which are basically identical to the iPad game but without all the text found in the screenshots on iTunes.