Unlockables In Gradius IV:

Gradius IV has unlockables. You must complete the following tasks and finish your game. That means if you don´t die, you won´t unlock anything, even if you have a saved game after completing the task. You should be careful too: If you load a game without a now unlocked feature, you will lose it again if you finish your game.

Effect - Code

Boss Rush - Complete the game
Stage Select - Complete the game