The concept behind Manhack Arcade is that it would be a space for oppressed citizens to blow off some steam and try to nab a high score in a popular video game, in which you control a Manhack as it slices up fugitives. Manhacks are those pesky flying drones that constantly accost Gordon in Half-Life 2, getting all up in his grill with their vicious spinning blades. Gordon Freeman was set to encounter a variation of this dark concept in the Manhack Arcade, a chunk of City 17 that didn't make it into the final game.
Kids think that they're just racking up kills in a militaristic video game, but they're actually wiping out enemy combatants with remote-controlled ships in a far-off skirmish. If you haven't read/watched/lived Ender's Game, one of its most fundamental concepts is (literary spoiler alert) a program that appears to be a battle simulation, but is actually a one-to-one representation of an interstellar war.
