First answer was correct .. too many ST shoot-em-ups didn't scroll the whole screen horizontally as "it can't be done" (check out the early examples, none used the whole screen and had a huge HUD to mask the fact that the game wasn't scrolling the whole screen).
All he did was adapt demo-screen methods and use it for a game (I'm guessing here) as most game coders weren't demo-makers.
When you look at the standard of demo menus (when it was the fashion) it put many of the real game engines used to shame.
My main site: http://www.mug-uk.co.uk
- slowly digging up the bits from my past (and re-working a few): Atari ST, Sega 8-bit (game hacks) and NDS (Music ripping guide).
I develop a free Word (for Windows) add-in that's available for Word 2007 upwards. It's a fix-it toolbox that will allow power Word users to fix document errors. You can find it at: http://www.mikestoolbox.co.uk