Hit an ally.

Call the police with a Streets of Rage 1 character.

Complete a stage without taking damage.

Get an S-Rank on all stages on Hard difficulty or higher.

Discover a retro level.

Get an S-Rank on any stage.

Clear all stages in single-player mode as Adam.

Use a barrel or a grenade explosion to kill 3 enemies at the same time.

Destroy all motorcycles.

Break the car in The Streets.

Beat Mr. and Ms. Y.

Use a wrecking ball to kill an enemy.

Break both elevator window panes.