Shameless Promotion, my new TF2 modded game mode -- Danmaku Fortress: https://www.youtube.com/watch?v=-5miEES5dpo
Since the 0.5 / 1 / 10 hour mill hasn't produced this one yet, I figured I would.
The song is known as "Cossack Sandvich" in the game files and may be known as "Soldier of Dance" elsewhere.
The mouse cursor is the KGB...or the CIA. Not sure which.