Silpheed Cheats

At the title screen, highlight Option. Press and hold buttons A, B, and C on controller 2, and then press start on Controller 1.

During the Intro Movie, press B - B - A - C - Up - Left - Right - Down - Up - A on P2. Begin a normal game and you'll be on the hardest difficulty.

During the introduction sequence, press: Down, Down, Up, Up, Right, Left, Right, Left, A, B, Start
Start a game, pick the stage, and press A to start there.

During the intro, press: Right, Left, A, Right, Up, C, B, Down, Left, B, A, Up, Start

During the intro, press the following on Controller 2: B, B, A, C, Up, Left, Right, Down, C, Up, A
Press Start on Controller 1. If the code worked, your starting score will read: 00001

Use controller two and do the following at the opening sequence

Play a Normal game until you lose and you only have 1 continue left. When the Intro Movie starts, press Right, Up, A, B, C, Left, Left, Down, C, A, Start. If done correctly, you'll get 10 continues!