After several marathon-length development sessions, MyDeadDog Software has finally finished its first game. Get In There stars an anonymous drunk who whirls back and forth in front of a strip club. When the player taps him with the stylus, he rockets up the screen in a lager-fuelled dash. If the player has timed their input correctly, the boozehound sprints through the pink front doors and disappears into the bowels of the building; if they haven't, he runs face-first into a brick wall, coming to an abrupt stop with a comic "SPLAT!". Either way, that's the end of the game.

Getting to this point has taken me approximately six hours.

To a certain extent, this figure tells you everything you need to know about WarioWare DIY. As with previous entries in the series, DIY allows the player to battle their way through hundreds of bizarre micro-games that tend to be about four seconds long; the main difference this time is that you get to build tiny challenges of your own. While there are also toolsets for making music and four-panel black and white comics, the key attraction here is the chance to make your own games. You'll draw out your own graphics, string everything together with a simplified AI system, and bung in a jaunty tune to play in the background. Your mini masterpiece has to be controlled by tapping the DS touchscreen (swiping isn't supported, sadly) and it has to fit into the limited time constraints, but aside from these limitations the world is your DS-shaped oyster. However, one thing is guaranteed from the outset: to get anywhere, you're going to need time, and a bit of dedication.

Naturally this is the same caveat that applies to any game or product that focuses on user-generated content. DIY comes with several sets of pre-constructed WarioWare games, and there are also several options for downloading other people's creations (more on this later), but for the most part your time is going to be spent crafting stuff of your own. Projects like these live or die by the nature of their editing tools; if they're too complicated to pick up easily, or if they're too limited to let you create anything of note, there's very little reason to get involved. Happily, WarioWare DIY scores highly on both fronts. It keeps things simple enough that it's fairly easy to understand the basics, and yet once you've got a bit of experience you'll probably be quite surprised at how flexible everything is.

Like most build-it-yourself offerings, DIY uses a points system to limit the amount of content that can exist in a single micro-game. After sketching out a background, your first port of call is to create the objects and characters who will star in your game. You take your pick from one of four frame sizes, then use an easy MS Paint-like set of brushes and tools to paint your sprites. A given object can have up to four "Art" settings - think of these as "modes", or perhaps "variations" - and each Art can have up to four frames of animation. For Get In There, the game I mentioned earlier, my Drunk character had three Arts: one for him whirling around (which used three frames), one for him running (which had two) and then finally one for him crushed against a wall. A complicated object like this will end up costing you quite a lot in the way of content points, but as a general rule the content allowance seems fairly generous. Besides, once you've got a few games under your belt you'll start to learn ways to be more efficient with your budget.

Once you've got your cast together, it's time to set up the AI to dictate how everything works. In simple terms, every object must be given a list of rules to follow under specific conditions. Each of these commands consists of a trigger, followed by an action. If you give your cartoon doggy a "Tap" trigger followed by a movement action, for example, the sprite will move when you hit it with the stylus. In that example, you'd also tell the dog how to move - randomly, or in a specific direction or pattern; you'd probably also tell the dog to change Art, so that it would display a "running" animation as it starts to travel.

On paper this may sound complicated and perhaps a little dry, but in practice these mechanics are both easy to understand and very gratifying to work with. There are several little moments of triumph to be found in DIY - the moment you first make something move in just the right way, and then a little later on the moment that you finish off your first home-made game. At each step of the way, the level of required effort increases - but so too does the pay-off.

Before you can have a go at making a game of your own, DIY forces you to sit through a number of tutorials, each of them divided into brief chapter-like steps. While these hand-holding sessions do drag a little, they manage to demonstrate a decent run-down of the raw principles without being too patronising. Still, there's no denying that the real gratification starts once this schooling is out of the way, as you set out into the great blue yonder to find your own way. Discovering certain tricks and effects is almost a game in itself, and wisely Nintendo and Intelligent systems have capitalised on this feeling by including a selection of set design challenges, in something called The Development Dojo. Here you'll be presented with a particular problem ("Make the ball roll down the hill and then across the bottom of the screen.") that can then be solved in a single step. Solving these puzzles unlocks fresh challenges and additional content, but more importantly it also teaches you techniques that prove very useful in your own projects.

In an even smarter move, you can also take any of the existing, pre-fabricated WarioWare micro-games and load them into the GameMaker toolkit. If there's a particular design issue you're facing and there's an existing game that uses a similar set of mechanics, this is often the simplest route to salvation. At the other end of the spectrum, there's also a wide selection of Wario's own half-made games that simply require a bit of work to finish them off - so if you're not in the mood to get your hands truly dirty, there's still a way for you to be creative in a slightly lazier manner.

Options like these abound throughout the various editing suites. The music maker offers a decent selection of creative options, arranged in the familiar "drop notes onto a horizontal timeline" format, but it also has something called the Maestro - an auto compose tool that generates music on the fly. If you can't be bothered to draw your own sprites, there are dozens of stamps and templates for you to pilfer instead. It all adds up to a commendably strong set of editors. Occasionally you do get the sense that things would be a lot easier if you were working with a more complicated toolset - ideally one on a PC, with a mouse and keyboard. It's impossible to rotate objects by anything other than 45 degree intervals, to give but one example, and since the all-important UNDO button only memorises the last thing you did, it can be quite tricky to amend the stupid mistakes that you invariably make. On the other hand, a proper Adobe-like setup would be impossible to use on a bus, on the toilet, or anywhere else that you take a DS - and it'd probably cost a lot more, to boot.

The only other criticism I can level at DIY is the relative difficulty in sharing your master works with others. It's not really the game's fault that the Friend Code system is such a massive pain to work with, but it's still a shame that it's not easier to pass stuff around. Still, there are already plenty of code-swapping topics on US-centric gaming forums, and with any luck there'll be a similar sense of community once the game takes off in Europe. If you can't be bothered with the hassle of Friend Codes, there's always the option to swap games locally, and there's also a soon-to-be-released WiiWare game, the snappily-named WarioWare DIY Showcase, that allows you to play your creations on the living room TV. If you've ever dreamed of offending your grandparents with your very own homebrew gaming obscenity, here's your chance.

Beyond this, there's simply something about WarioWare DIY that inherently works. Maybe it's the limited time format, or the fact that the series has always been driven by its own oddball sense of humour, but somehow the scrappy nature of user-generated content is a perfect fit for this franchise. Over the last week I've found myself sketching angry frogs, flying brains, and in one particularly puerile development session, animating a set of male genitalia. This is a game that feeds on your imagination, that encourages you to explore any idea you might have, however daft it may seem. And on top of all of that, it ends up teaching you a few things about basic game design.

It's also worth pointing out that the whole process quickly becomes hugely addictive. At the end of last week I was at a station and had some time to kill before meeting a friend, so I decided to do a bit of work on one of my projects. I found a seat, opened up my DS... and suddenly an hour had rocketed past. The platform I was on had actually been closed off, so I had to get a guard to unlock the gate. It really is that absorbing. This kind of venture isn't for everyone, but if you've got the ideas and the patience to make them work, WarioWare DIY will keep you tied up for months.