Hitman: Absolution HD (EP)

This can only be obtained after the first level. You must cause mischief/chaos within an area. Run around being careless, shooting people, not sneaking around, etc. Enemies will become hostile and attack you. Kill all enemies and once things are back to normal, the achievement unlocks. See "One With the Shadows" for similar achievement but hiding from everyone. This is best done with a low amount of enemies around.