Some of these are really impressive. There have been several surprises where the developer(s) went the extra mile in ways that are surprising. Like in Lossst, when finishing a level, it'll zoom the camera to the next door and back to the worm. It's amazing that someone working within such a tight limit can think, "I know, we'll do this nice zooming thing which has no real relation to game play but will feel nice!"
JS has gotten incredibly concise in recent years. I've noticed it on codefights.com, where a lot of the shortest entries are JavaScript (and very few are Perl, which surprised me, due to Perl's long golfing history). I'm constantly struck by how tightly all the pieces work together these days and how much you can do with so little.
Thanks man! I made this game by (ab)using the power of CSS and CSS3D, and really focused on the player experience, so I'm glad you enjoyed it! If you continue playing, you'll see even more surprises :)
Also, here's a making-of: http://xem.github.io/articles#js13k17
Couldn't get past the first level. What am i supposed to do? What's the puzzle? Seemed like a dead end to me, all the doors had numbers greater than my length. How am I supposed to increase my length?
JS has gotten incredibly concise in recent years. I've noticed it on codefights.com, where a lot of the shortest entries are JavaScript (and very few are Perl, which surprised me, due to Perl's long golfing history). I'm constantly struck by how tightly all the pieces work together these days and how much you can do with so little.