G-LOC: Air Battle (Sega Master System)

G-LOC: Air Battle
Also known as: G-LOC (BR) Developer: Sanritsu Denki Publishers: Sega (EU), Tec Toy (BR) Platform: Sega Master System Released in EU: 1991 Released in BR: 1991 This game has debugging material. This game has a hidden sound test. This game has a hidden level select.

Test Mode

At the title screen, press 1, 2, 1, 2, 1, 2, 1, 2 on controller 2. A sound test will appear and a few functions will be enabled on controller 2 during gameplay: press 1 to instantly complete the current level, and press 2 to change the type of terrain.

(Source: SMSPower)