Super Star Soldier

Super Star Soldier
Developer: Inter State Software Publishers: Hudson Soft (JP), NEC Home Electronics (US) Platform: TurboGrafx-16 Released in JP: July 6, 1990 Released in US: 1991 This game has a hidden sound test. This game has a hidden level select. This game has regional differences.

Hidden Menu

At the title screen, press Left, II, Up, II, Right, II, Down, II, Left, I, Up, I, Right, I, Down, I, then press I + II eight times followed by I + Select eight times for a hidden menu containing a Sound Test and difficulty setting.

(Source: GameFAQs (AWing Pilot))

Expanded Hidden Menu

Hold Run+Select before powering on the console, then enter the above code to add a screen size toggle and level select to the menu.

Regional Differences

PC Engine	TurboGrafx-16

A "FROM NEC" credit was added to the title screen right above the updated copyright info.