hidden areas, Quake II, first-person shooter, secret rooms, hidden weapons, power-ups, armor shards, health bonuses, ammo packs, game environment, industrial structures, alien architecture, dark corners, secret triggers, hidden buttons, secret passages, wall textures, hidden platforms, exploration, sci-fi setting, atmospheric lighting, metallic surfaces, rusted pipes, concrete bunkers, military base, alien compound, lava pits, immersive sound effects, hidden collectibles, Easter eggs, interactive objects, secret level entrances, hidden caches, strategic advantage, surprise elements, reward exploration, enhanced gameplay experience.