Version tested: PC
The first thing you should know: The UnderGarden is a game. That may seem like stating the obvious, but it's true. Every mention of the game so far has made prominent use of the word "casual", usually followed by any combination of "ambient", "trippy" and "chilled out". The impression given is that it's more of an interactive mushroom experience and not the sort of game to totally harsh your buzz with downers like objectives and completion ratings and woah man, just relax, OK?
And to begin with, that seems like a fairly accurate description. You control a chubby alien pixie thing, able to float through the air in a garden that makes Avatar's lush luminous jungle look like a manky old lettuce and a couple of dandelions. It's a sumptuous, wondrous environment and one that immediately rewards exploration.
Bounce off a green blob, helpfully brought to your attention by the minimalist tutorial, and a cloud of pollen ejaculates lazily into the air. As you scoop it up, each piece gives off a tinkling chime, an escalating sing-song scale that makes the game's key mechanic a tactile joy.
Once carrying your fill of pollen, the garden bursts into life whenever you pass by dormant flora. Tendrils burst excitedly from the walls and floor, carpets of glowing grass pop and sway with evident joy. Each comes with its own sound, transforming your movements into musical flourishes that feed into the relaxing soundtrack.
It is, frankly, beautiful and the simple pleasure of making stuff happen ensures that the first few minutes of play go a long way to winning you over. It's a game to sink into, like a big soft duvet and the prospect of blissful sleep after a night out when you're still just mashed enough to feel snuggly and content.
Gameplay introduces itself very quickly, but never intrudes into this enjoyable cocoon. There are trees in the game which bear fruit once the plants surrounding them have been pollinated. Different fruit have different effects, and can be carried by extending a small circle of influence around you. Anything that can be picked up in its radius attaches to you with a little glowing string.
To begin with, it's simple stuff. Heavy fruits can be used to weigh down pressure pads, while lumpy helium-filled fruits act as balloons and can be used to lift switches in the opposite direction. After a few basic physics puzzles in which you navigate tunnels and trapdoors using these rudimentary tools, The UnderGarden begins to show off its full range of produce.
Lantern fruits light your way through deadly dark passages. Energy fruits carry an electrical charge and can be used to power up organic technology. Exploding fruits do exactly what you'd expect, detonating with very un-chilled-out force when dropped, demolishing walls and sending gameplay objects hurtling through the air.
The game also starts to hinder your progress in a firm but gentle sort of way. Gusts of wind prevent you from travelling in certain directions, or carry you along like an autumn leaf. Cogwheels must be turned to open passages and lock doors in place. Glowing pods cause you to drop everything you're carrying, including pollen, should you bump into them.
From these simple yet interlocking abilities and obstacles, the game begins to reveal the structure beneath its mellow shell. The aim is simple – get to the end of each level, pollinating as much of the world as you can. The execution, while never truly difficult, is challenging enough to make a mockery of the idea that this is a blissed out paddling pool for the off-yer-tits crowd.
Reaching the end of each of the game's 14 stages isn't going to trouble you for long, but finding all the hidden crystals and special flowers while pollinating every plant is no mean feat. Cleverly, such completist goals are not essential. If you want to enjoy the trip, you can.
All of these collectables are tucked away down optional pathways, hidden behind slightly tougher environmental puzzles, but can safely be ignored if you don't want the trouble. For those who do take up the challenge of 100 per cent completion, unlocking different skins and horns for your pixie as you go, you're looking at a play time that easily rivals the single-player campaigns of certain angry, noisy blockbuster shooters.
It's not the gameplay challenge that frustrates, but the game does feature some niggling quirks that take the edge off its dreamy soporific fugue. Mouse control on the PC isn't great, and navigating some of the twistier sections while dragging a cloud of fruit can be a snaggy affair. The game's camera also has a tendency to zoom out at fixed points, revealing the next large section you'll need to pass through.
That's fine, but it means that trying to carry out any fine movements in these boundary areas becomes a real fiddle, as the viewpoint lurches in and out every time you nudge over the trigger point. It also means your movement pointer changes orientation, as it's attached to the camera, not the character. Navigation, inevitably, takes a hit. It's never fatal – you can't die in The UnderGarden – but anything that breaks that comfortable immersion feels more noticeable thanks to the game's snug ambience.
The UnderGarden is also sometimes too obtuse for its own good, giving you the basics but neglecting to explain which elements are there for show and which are tied to your score. There are two similar gauges at the bottom of the screen, for example, and the game doesn't bother to tell you what they show.
More mysterious are the musicians, tiny pixie characters found sitting in the gameworld, burbling along on little musical instruments. Their music feeds into the soundtrack as well, and grows louder the closer you get to them. Pick them up and the foliage blossoms and dances as you pass, while weird frogspawn things become magnetically attracted to you.
Like all the interactions in the game, it feels immediate and rewarding, but it also feels important. Am I supposed to save these guys? Take them somewhere? Or can I pick up and drop them as I please?
The UnderGarden isn't telling, and it's here that the world of rigid game rules and free-form ambient experience chafe slightly as they rub against each other. Allowing the player to discover how the game world works is fine. Leaving them unsure as to where their obligations, if any, actually lie leaves a slightly distracting and muddled "am I doing this right?" feeling at the core of an otherwise lovely game.
Still, The UnderGarden is an undeniably lovely place to visit and one that provides more gameplay structure than you might expect. It doesn't always succeed in finding a balance between its chilled-out exploration and OCD completist tendencies, but when the formula clicks, the result is both charming and visually stunning. It doesn't quite deserve to be ranked alongside spiritual forebears such as LocoRoco and fl0w, but it comes close enough to make a few evenings basking in its warm glow an easy recommendation.
7 / 10
The UnderGarden will be released on 10th November on Xbox Live Arcade for 800 Microsoft Points (£6.80 / €9.60) and on PC for $9.99 via Atari.com. It will be released on PSN in 2011.