WarioWare D.I.Y. does for making games what the original WarioWare did for playing them. The series has always been about distilling the act of gameplay down to its simplest elements, so that a game can be learned and completed in five seconds or less. In this case, a simple, menu-driven interface, combined with the harsh time restrictions of the games, allows you to go from idea to full (but tiny) game in just minutes.
After about an hour of tutorials (or, actually, somewhere halfway through), you'll have enough of a handle on the concepts of the game's utility to make a game. The tutorials walk you through the creation of three sample minigames step by step, with instruction from Dr. Crygor's granddaughter Penny and distraction from your fellow student Wario (the only Nintendo character who could get away with taking an emergency bathroom break during a tutorial). For further instruction, the game features a series of "challenges" in which you fill in one incomplete aspect of a more complex game.
Not that you need too much of a tutorial: the tools are so easy to understand that pretty much anyone, regardless of age or programming knowledge, should be able to make a game. The secret is the menu interface for "AI," with which you assign actions to your created objects (like movement, sound effects, or art changes) and triggers for those actions (tapping on them with the stylus, contact with another object, time, etc.) On their own, each action and each trigger is easy to understand, and they can all be stacked to create complex interactions -- even if, say, your only qualification as a programmer is that you married a programmer. Here's a microgame I made as proof.
The drawing and music interfaces are similarly streamlined, based entirely on icons for familiar drawing actions (and Mario Paint holdovers like the rocket eraser) and dots on a grid to represent music notes.
The tools are so easy to understand that pretty much anyone, regardless of age or programming knowledge, should be able to make a game.
There's so much I have yet to talk about -- the fact that you can share minigames through the DS or Wii, that you can play them on the Wii with WarioWare D.I.Y. Showcase, the ability to make short comics and songs in the game's editors. Especially considering its origins as the most bite-sized game ever, D.I.Y. is absurdly feature-packed. As cool as all that stuff is, however, it's all contingent on one aspect: whether the editor is easy and enjoyable to use. Thankfully, it is. Anyone with any amount of understanding of game design or programming can make a game in very little time. It works. The game does what it says on the tin, as they say.
In conclusion, here's a microgame demonstrating how I hope you'll respond to this little writeup. Now, if you'll excuse me, I've got a hot game idea about checking your pockets for loose change.
This review is based on a retail build of the DS version of WarioWare D.I.Y. provided by Nintendo.