If anything happens when you complete all seven levels of Seven, then I don't know what it is. Because I've tried to finish level 6 until blood came out of my ears. However, the other six levels I found to be simple and charming (with the possible exception of 4, which seemed a little silly). But perhaps I'm doing something spectacularly stupid - I am, after all, spectacularly stupid. But I suggest having a go at the web-embedded platformer to find out for yourself.
The biggest problem, so far as I can tell, is the glitchy jump. Of course the occasional lag could be as much my stroppy connection as the game, but there's no doubt that oftentimes hitting Up for jump has no effect at all. This is usually not a problem, but for level 6, which appears to require precision jumping across blocks that pop in and out of existence. I have sworn. Loudly.
However, that shouldn't entirely tarnish a rather cute, short-ish 2D platformer built out of 3D blocks. It has a charming patchwork quality, as if sewn together from bits of left over graphics from other projects. Go see what you think. Via the ever lovely Indie Games.