Well Nich, it's simpler that you think, Psygnosis wanted a c64 and zx version; Clockwize thought that at the same time, they could deliver a CPC version too...
... but when they showed the 3 versions, Psygnosis said that what they really said was "we want a c64 and zx versions, and we DON'T want a CPC version"...
Yes, it was a super stupid move by Psygnosis, but they were the guys paying and Clockwize had to respect that, even if it's so difficult to understand why they would not want an extra port for a system that they had released games before and after Captain Fizz.
Because of that negative, everybody should understand that Clockwize had to stop any extra development time in Fizz CPC, because they would not get any money of this great CPC game. And that is the reason because all the loading screens, except the one for choosing language, come from zx; they were temporary screens, and if Psygnosis would have bought the CPC version those screen would be very different.
And i can tell you that Dean and me spoken about making a nice mode 0 pictures of those, but at then end we thought that it would be much better to preserve the games as they were, because after add the screens, we could fix more things and more, ... and then we will reach a point where we would have crossed the limits of preserving the original game.
Of course, now that the original release is preserved, if somebody wants to make new screens, feel free and use those in your cracks/HD installers/...
One thing, that i would love to say is that all those Clockwize games looks finished, but that is not really true, those games remain in the same state that when they were brought to possible publishers, if the publishers would have given the go on, then extra time would have been taken for polishing/improving those games.
For example, because Ninja Grannies never got a publisher (*) and new games contract came, then Clockwize never had time for improving the playability/difficulty (that trick kick

) or adding a two players mode, ...
(*): Not getting a publisher for Ninja Grannies is another thing that i will never be able to understand, because NG is a lot better than a lot of CPC fighting games... I love that wink to "Hell's Grannies" Monty Python's sketch, hehehe.
At the end of the day, i enjoyed to help discovering/preserving those games, but i loved even more to discover about the dynamic duo, Dean and Dave, and about the story of Clockwize, one of the less known game developers from the 80.
A company that thought that the CPC was a great machine, something that you can see in those MIAs games, games with a lot of polishing and nice details that are not usual in CPC versions of games designed originally for other machines. And even after Clockwize closed, while Dean and Dave were adjusting to their new lives outside of game development, they made Frogger and Unpredictaball for CPC, even if they liked and coded for all the 8 bits machines, those guys chosen to code for the CPC in their free time.
I promise that has been a big inspiration to discover about a company that loved the CPC, so much, that maybe a few choices, that they made, were not the best for business, but when we were young, we used our heart a lot... Thanks Clockwize! Thanks Dean!
