Continue
On either the Game Over screen or when it flips back to the Title screen, hold A and press Start.

Stage Select Plus
When the Title screen appears, press Up, Up, Down, Down, A, B, A and B. Then hold A and press Start. "W 1-1" will appear in the top-left corner, indicating that World 1-1 is the current stage. Press Up/Down to change the stage number, then press Start to begin. This allows you to begin your game in the stage of your choice. You will also begin with 80 fighters in reserve as well as 90 miracle kicks.