Mightier is a little 3D game in which each level contains a number of object you must retrieve. You begin at level zero, and while you can jump as high as level 1, many objects are at higher levels.
Scattered about the field of play are "crystal pillars," all of whom begin also at level zero. ESCing out brings you to an interface where you can draw closed loops about the play area, each loop containing a pillar and one (or more) of the retrievable objects. Once you have done so, the application interprets your drawing, and then you view a scene in which a laser from space zaps the crystal pillars, "raising" them to a different level. The idea is that you create platforms that allow you to jump up and grab the objects you're after. The platforms are the same shape and size as the loops you drew.
What's original about the game is also something that doesn't work, really. If you want, you can print out the level layout, draw your loops with a pen or pencil, then scan the result in (or use a web cam to image it), then submit the image. Thus, the game is trying to integrate digital gameplay with pencil-and-paper puzzles. Alternatively, you can use a little in-game draw program to draw your loops. Which you mostly will.
The puzzles themselves are trivial; I mean, I have no objection to pencil-and-paper puzzles, do the crossword in the Times almost every day, and used to enjoy logic puzzles. But solving the geography of each puzzle is fairly obvious, and not worth the time and energy to go through the print-and-scan process.
There's only one reason to do so, really; and that's the same reason that the game is frustrating. If you do, you have a map that shows you where the platforms are, which you can refer to as you run about the level. The digital game itself provides no visual representation of where the levels are, other than height differences in the pillars, which are located in the level but give no hint of its geography. As a result, quite often you fall down to a lower level because of a small gap between (which you could have jumped if you knew it was there), and have to circle back around to the pillar that represents level 1.
On the whole this is not a satisfactory game -- but it is, at least, an attempt to do something novel, and interesting in that regard. And you can at least imagine that a game with richer puzzles using the same basic scheme could be better (or a game with clearer representations of existing platforms). In fact, it makes you think that, with the variety of input and output devices available on modern PCs, it's perhaps remarkable that so little use is made of anything other than the mouse and keyboard. Is there more that can be done with alternative UI, even without something like a Wiimote?
Update: Mightier is now a 2009 nominee for the IGF in the "Innovation" category.