Few of us will think much about the liquids we use. We fill our vehicles with oil and gas, use water to brew our tea, pour detergent into the necessary appliances for clothes and dishes, and dump drain cleaner down the tubes. We take it for granted that these fluids flow into the assortment of everyday items they're used with. In basic terms, it's nothing more than the simple assembly of elemental cause and effect.

But suppose for a minute that there exists a secret life of liquids, a journey that occurs whenever we perform one of those most basic of utilitarian actions like pouring soap into a dishwasher, or even when, say, rainfall flows into a drainage pipe. Where does that liquid go, and how does it get there?

This is the idea behind Puddle, which follows various liquids through their own quests to arrive at their final destinations. The idea may sound familiar - WiiWare's Fluidity used a similar premise that let you control water in various states. Thankfully, Puddle has none of Fluidity's ridiculous narrative elements.

Of course, in real life the unseen world of liquids isn't interesting. The boiling water goes from the pot to a teacup. Gas and oil flow into appropriate tanks or reservoirs to help power a vehicle. The soap is distributed throughout the dishwasher once it's turned on. The whole process is usually taken care of by gravity and engineering.

This isn't how Puddle operates, of course. The design itself is based entirely around mastery of some very impressive physics - all you do in this situation is tilt the screen at a left or right cant and use gravity, momentum and inertia to navigate your puddle through increasingly taxing obstacle courses.

The game starts when you knock a coffee cup over in a lab - the liquid is then (presumably) purified into a clean state, which you have to guide through a complex series of lab courses.

Controlling liquids is easy at first. They will pass over heated areas (as you might imagine, these will kill your liquid volume with too much exposure), stream across gaps, through tubes and around half circles - these are similar structural elements to a classic Sonic game, only here the blue hedgehog is a gelatinous goo blob you can't control directly.

The dev team, who won the 2010 Independent Game Festival student showcase for their work here, clearly had a lot of fun making Puddle. The game revels in its creativity, always throwing you new things to consider: In the second world you're suddenly controlling a puddle of pesticide, which breaks down natural barriers; fertilizer seen later helps grow plants which push your liquid blob along.

As the game progresses things get even more interesting - eventually you'll be changing states on the fly with a rapidly cooling molten alloy, transporting chemicals in lab beakers or dealing with zero-gravity situations in space,. Boss 'battles' are a particular treat, and usually involve the practical application of liquid physics to, say, overload a hydro-electric machine, or use liquid dispensers to open and close barriers on a moving conveyor belt.

The only downside is that Puddle can be a challenging game. Not being able to directly control your liquid plays a part; the real problem is that the level design becomes pretty nasty.

Late in the game you guide some especially gelatinous rat goo (please don't ask) through some sewers that, for some reason, are teeming with buzzsaws on rails that will destroy your puddle in a flash. The idea to get around them is to use air vents to spring your goo over the obstacle, but you also have to time the lift and momentum so you don't dive straight into the saw's blades. Then you have to essentially float your goo up a wide airshaft using crosscutting vents.

Or consider the molten alloy levels, which require you to move quickly before your liquid cools. That's fine, but at full temperature the high viscosity makes keeping your blob intact while running an obstacle gauntlet next to impossible. Fortunately most levels can be finished within a minute or so - it's just not always easy making a perfect run when odds are stacked so high against you, and the only control you have is the slant of the screen.

Puddle is a well-made game with a lot of character and a cheeky scientific feel. It's fun to see what sort of unexpected places and states you end up in, but be prepared to suffer a lot if you want the medals on every level.

Version Tested: Xbox 360