Instructions
Start "Super Smash Bros. Brawl." Click "Solo" and select "Adventure Mode: Subspace Emissary." Click "New."
Enter a name to save your progress when you quit. Choose the difficulty, from "Easy" to "Intense." "Normal" difficulty is selected by default. A cinematic will begin.
Choose between Mario and Kirby. You will fight whoever you didn't pick. After the fight is finished, you will watch another cinematic.
Select the order of the four characters you wish to play as. When one character dies, you will play as the next character you picked. For example, if you choose Mario as character number one and Peach as number two, you will play as Peach if Mario dies. Once you choose the order of your characters, you will begin fighting various enemies.
Kill 30 enemies and a boss will appear. Defeat the boss to complete the stage. Once you complete the stage, the next stage will unlock. Complete each stage to unlock the next one. Eventually you will unlock all of the stages. Some stages do not feature a boss, but rather a golden exit door. Once you go through the door, you will complete the stage.