This is a Minecraft map created by a group of friends to allow "Two Rooms and a Boom" to be played over the internet. The basic rules are this. The Red Team wants their Bomber to end the game in the same room as the Blue Team's VIP. If the Bomber and VIP end the game in the same room the Red Team wins. If they are in different rooms the Blue Team wins.
The mod "MumbleLink" and use of Mumble for talking is recommended for the most genuine way of playing the game. However, you can play without using a voice chat service. Mumble Link is used for the positional audio to make keeping the rooms separate easier and to emulate whispering.