Oh! Closure.
It took me a while, but I finally did "get" the name: light sources create their own little, enclosed bubbles of reality around them. This becomes more poignant in levels with water, where you'll literally float within the light, but cease to exist outside it.
Anyway. Closure's light mechanic is devilishly clever, and the game does a pretty satisfying job of finding new twists to put on it, through all 82 of its puzzles. Some are a bit of a cakewalk (a few levels are, in fact, just an arty show-off where you walk to the exit), but the puzzle design on display here is really top-notch.
What dulls that notch, though, is the game's lack of forgiveness in some excessively complex puzzles. Restarting a level seems easy enough at first, but later puzzles involve painstaking, meticulous setup to solve, which can be irrecoverably ruined with a single misstep, like dropping an item in the wrong place. On a few occasions, it even seems like the game's physics are working against you, as the carefully-planned drop of a box results in said box bouncing off into the nether. If any puzzle game was ever in need of a Sands of Time-style rewind feature, Closure would be it.
The only other disappointment I have with Closure is its story, which I'm not really sure exists. The art style hints at some deeper meanings behind your character, and behind the themes of some levels, but there's no ... well, no closure on these ambiguous concepts; just self-referential callbacks. It's pretty, but seems hollow.
But these shortcomings can only do so much harm to the game's brilliant design and pleasant style. Closure is a fulfilling puzzle challenge, and artistically striking as well. Really, it's nice to have a platform-puzzle game that isn't all happy-go-lucky, for a change.
Better than: Unmechanical
Not as good as: Offspring Fling!
Really, what's up with the character theme: is it about a workaholic dad and a pill-head/insane mom, whose daughter turns to dark fantasy? Seriously, I don't get it.
Progress: Finished all puzzles, collected 7 light moths.