Sega Master System / Mark III / Game Gear
Press at the title screen.
Successfully complete the game, and choose the continue option to begin at Level 00.
Press , then or , at the title screen.
This cheat can only be done if you have an FM chip (Japanese or Korean systems). Hold on Controller 1 and on Controller 2 when you turn on the console.
See the main page for Power Strike / Aleste (アレスタ)