Winter Chip XIII is now free. So if you didn't want to pay the initial 1$ price tag, you can go pick this up for free from Battle of the Bit's bandcamp page.
This is a huge compilation of 50 entries from the huge Winter Chip competition this past December.
Typically BoTB releases are free until the next one comes out, so get it now while you can.
Pick up Winter Chip XIII from the bandcamp page here.