Every now and again, when I play some games around Christmas, it turns out that quite a few of them have various easter eggs that activate only during that particular time. Although I'm sure it is but a sheer coincidence that only old games have them *glares*
I particularly laughed last year when I loaded up Crusader: No Regret, and it greeted me with a secret track:
Another one is Tyrian, where you can activate 'Christmas Mode' that changes all guns to candy canes, snowballs, etc
The main menu screen in Worms Armageddon also changes slightly.
^ While usually you have mostly random things falling in the backgrounds, during Christmas it always snows.
I also think I remember a Christmas special in one of the build engine shooters, although I don't recall which one and how it worked.
Post some more!
I particularly laughed last year when I loaded up Crusader: No Regret, and it greeted me with a secret track:
Another one is Tyrian, where you can activate 'Christmas Mode' that changes all guns to candy canes, snowballs, etc
The main menu screen in Worms Armageddon also changes slightly.
^ While usually you have mostly random things falling in the backgrounds, during Christmas it always snows.
I also think I remember a Christmas special in one of the build engine shooters, although I don't recall which one and how it worked.
Post some more!