This game is a simple idea done right. The the name of the game here is that touching the light gets you killed. The light behaves how you'd expect and the game does a good job easing you into this concept.
I like how instantaneously the light wraps around corners. It can seem that you are safe but then the next moment the light touches you and you're dead. I also like the puzzle-like nature of the game and I had to wrack my brain to figure out how to get through all the levels. I find this game difficult, but not exceedingly so.
Visually, this game is a good example minimalism done right. I think the melancholic atmosphere fits the gameplay well. And the light looks satisfyingly cool. A gripe I have is that the triangle is black and so are squares and terrain which makes the player blend in. I think the triangle should have had an outline and a white dot in its center showing where the hitbox is.
I managed to complete all twelve levels and collected all the collectables in five of them. I don't think I have it in me to collect them all ^^;
I enjoyed myself with this game. I have a hard time seeing this as a full-length commercial release but as a fun demo it fulfilled its task.