It is a hidden movement game, akin to Captain Sonar. There is a square grid of tiles, and you move around it in the typical 8 directions. Each player is told the color of tile their opponent moved to (you cannot reuse a square). If you move into your opponent, you win.
You have the ability to "pounce", jumping like three squares, but doing so will announce your exact location, so if you miss you will be dangerously exposed. There are also bonus pickup on the map with various powerful effects, but picking them up exposes you, same as a pounce.
I presume your company is using Cisco Umbrella DNS? (It's blocked for me too, and that's why. Umbrella has a "feature" that automatically blocks any newly-seen domains for the first few hours of their lifetime. Presumably they do some extra scanning of said sites, and assuming they're safe unblock them after a few hours.)
Can I get a description of what this is like?