I hope you're ready to not get any work done, because Dojo of Death will absolutely eat up any productivity you thought you had.
The game is a very simple one. You're a ninja, against a horde of other ninjas. Click to slash through them or deflect arrows. One hit, and you're Ninja fertilizer. Simple enough, sure, but sometimes the most addictive games don't need all that much to get your attention.
Have fun. Try not to get fired.