Unity, ~300 lines of code.
Other tools: Inkscape, GIMP, Sfxr.

What went right:
For my 2nd Ludum Dare I wanted to be more adventurous, thinking harder about the theme interpretation than I did for LD 29 (where I just made an arcade game which vaguely used the theme). I did not use my first few ideas, or rush into it. I went away from my desk to think. Finally, I decided on a genre new to me; a slower-paced puzzle/adventure based on dreams, with some narrative elements and a real ending.

Overall, I’m fairly happy with the end result, and I enjoyed working in a different genre. I think the game successfully conveys what I was aiming for, and uses the ‘connected worlds’ theme in multiple ways. I took some inspiration from games like Journey and Dear Esther (walking simulators..?), and even the ‘P.T.’ teaser — all those repeating doors and riddles!

The controls are simple, no complications there. The graphics took a long time to make, but I was aiming for a dream-like style. However, some of the filters are used to simply hide my dodgy drawing . I did not attempt 3d models this time (next time!).
There were no major problems in Unity, except my general lack of experience and a few crashes. The scope of the game was correct for the time available, I didn’t feel too rushed on the 2nd day. I only wasted a bit of time on mechanics that didn’t make it into the final game.
I created just 2 sound effects, but I thought it was enough (less is more??). Bad music would just detract from the game.

What went wrong:
I originally planned to use a range of interactions, e.g. having the player’s controls transfer to the other people/items in the scene. However, my initial attempts just didn’t look or work right, so I had to re-think it all on day 2, which is never the best idea.
The creation of the graphics was both good and bad; its not quite as nice as I would like, but it has a mostly cohesive style. The colors and shapes could’ve been stronger. The game doesn’t really use full 3d, all the graphics are flat sprites in the 3d scene.
Didn’t get a chance to get much feedback from players before submitting the final game.
Finally, I slept really badly on Saturday night (ironically enough), so I wasn’t exactly feeling 100%.

Play it here: http://www.ludumdare.com/compo/ludum-dare-30/?action=preview&uid=36950

** SPOILERS!! Play game before reading! ** The stages in the game are of course a metaphor for sleep stages and trying to wake up. The other figures are memories of friends etc in your dream, or perhaps other dreamers. You cannot trigger the final stages by passing through the windows/portals alone, you must enter just after another figure has passed through from the other side, i.e. whilst you are both still glowing (‘connected worlds’ again). Who knows, maybe this process helps you sort out your memories, then finally conclude your dream…