Games with unlockable holiday goodies?

[dsheinem]

Ok, so I know there are a number of games out there that give you goodies/special modes if you fire them up around Christmas/Halloween/Easter/Whatever - but I thought a list of them would be a cool thing to compile for a thread...

...Lo and behold, TVTropes did it for me: http://tvtropes.org/pmwiki/pmwiki.php/Main/HolidayMode

The ones that I was most familiar with are:

Christmas Nights
Rise of the Triad
Animal Crossing series
Team Fortress 2 (hats, etc.)
Shenmue

Today I am going to try a few of the others listed on the site (Cave Story + sounds like it would be cool), and I'm curious if any of you have tried these or stumbled across holiday goodies not mentioned on the site. Share your experience here!

[MrHealthy]

Cave Story+ completely redos the tile set / character sprite today. Its an impressive ammount of work for one day of playing.

[J T]

Tyrian 2000 says "activate christmas?" when you boot it in December. If you type "yes", then your ship will shoot candy canes instead of bullets.

Dirt 2 gives you a Christmas tree bobble-head toy for your dash.

Killing Floor does some Twisted Christmas thing with evil Christmas characters.

[Jontendo]

In "Ready 2 Rumble Boxing: Round 2" (Dreamcast).

Christmas Ring (entered at character select screen): Right, Up, Down, Down, Down, R, R, R, R, R, R, R, R, L

[elmagicochrisg]

In "Ready 2 Rumble Boxing: Round 2" (Dreamcast).

Christmas Ring (entered at character select screen): Right, Up, Down, Down, Down, R, R, R, R, R, R, R, R, L

In the first one you just had to set the internal clock of your Dreamcast on december 25th.

[CD AGES]

Yup! Didn't VOOT have similar thing when setting the DC clock during Halloween or on dec.?