1984 Parker Brothers
Platform: Commodore 64
Not quite a GTW64 entry, but an earlier build of the released Gyruss (a brilliant Konami arcade conversion) for the C64 – recovered thanks to preservationist Ken Van Mersbergen.
This prototype dated 2nd May 1984 was found within the collection of disks/materials from the archive of a retired programmer who used to work for Roklan and On-Time Software.
There doesn’t seem to be much in the way of differences that we’ve found so far apart from slightly different attack waves.
Professor Chaos got in touch via the comments to say that there are two differences to the final version and described by him as “theoretical or VERY rare glitches”. One in particular was where it goes straight to a level complete animation when all the enemies finish exploding.
In the final version, an extra check is added to make sure you are still alive (as you could still run into an enemy shot for example). Another difference was the removal of some code that when an enemy’s sprite block is blank, it’s y-position is set off-screen. Professor Chaos suggests that maybe this was unnecessary and removed to make room for the above fix in the first difference.
So, not a major difference to the final version at all – but good to see these different builds preserved, as you just never know what may surface.
A huge thank you to Ken Van Mersbergen for his fantastic preservation work and for preserving this prototype. Thank you to Professor Chaos for checking through the code and highlighting the minor differences present.