30 lives, player one:
At the title screen, press Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start
30 lives, player two:
At the title screen, press Up, Up, Down, Down, Left, Right, Left, Right, B, A, Select, Start.
The Genie has more
Gradius 2 Cheats at CheatingDome.com.