Final Zone

An overhead/isometric mech shooter with no relation to the last stage of Sonic the Hedgehog.

Invincibility... sort of
Enter the Options screen and press A, Start, A, and C without pressing anything else beforehand. A sound should confirm this. While you will still take damage at first, the game will not kill you — once you get to one health bar left, the game will stop taking away health.

Stage Select
Enter the options screen and press C, C, Start, and B without pressing anything else beforehand. A sound should confirm this, and you should see a new MAP option listed, which will let you choose the starting stage.