[b] !!! Important Edit May 2014 !!!
Seems like the link does not work on the download button, which is odd. Here's a link to the map page on garrysmod.org site( you have to log in with steam to download it).
If there are problems and the map gets deleted or the link doesn't work, please PM me!DOWNLOAD LINK => LINK
This is a map I made because of the joy of the holidays ! ( last year I made a cs map for the same reason).
I know most of you don't own Garry's Mod, but for testing or things like these, you can extract only the bsp. ( yes, it works in hl2, gmod is based on hl2 maps ...).
Of course, you could say it looks miserable, but gmod is a sandbox. The map serves only as a support for fun things.
There's a readme included in the zip.
[EDIT] Video ! : http://www.youtube.com/watch?v=ADqVC0DLNYU