The idea is this. A 1:1, 2:2 or 3:3 match is spun up on a small map where the fighting begins and ends in a series of minutes. All of the Hl2 weaponry as well as my own additions would be added in to accentuate the maps size and need for weapons that work immediately. The maps have to be small to maximize the fighting but it pretty well forces a battle with little other than that to do. The battles would be fought and end quick enough that spectators can be added in and actually have something to do, other than helping one side cheat.
Depending on how things go, it may not even be necessary to make all maps cubes (I would lean away from this anyways). We could go through some of the popular mods and see where their battles are being fought and build just that section of the map. You can picture the concept behind this in that famous video game animated journey Reboot, where the elongated and Shader wrapped cube falls in from the sky and Bob tries to race the clock and artificial gravity to get into the cube before the people of their city fall victim to… the user.