Mystery solved! This has to be what Blizzard is teasing on their website - World of Workcraft - the game World of Warcraft characters play when we aren't looking. The ice is obviously the freezer in the break room in desperate need of defrosting.
I agree with the commenters over at WeGame. This definitely needs a sequel, if only for more Arthas.
World of Workcraft [WeGame.com - Thanks Chilly!]