Alrighty! I have questions. How on earth have you accomplished this? It's a perfect copy, down to even the exact same attraction mode recording (even wondered if it was a recording as a kid). It's like you have the source code to the original? Have you disassembled it somehow?
Anyway, here's my findings.
The gameplay look survived perfectly. :3
There are some slowdowns that I had not seen on the CPC 464, but they are not too terrible, and if they are simply because of the different CPU and speed, then I guess it cannot be helped.
There are graphics artifacts, such as leftover flying bits when monsters get smashed (like by an apple). The highscore table background is white, not black, like on the title screen. Name entry would normally also be done on black background. Also, the title animation here is considerably choppier than on the actual title screen, it's all good there.
The title screen, gameplay instructions are somewhat slower than I remember them.
Some graphics might benefit from some manual touching up by hand (I know the pallette is more limited) as they look a bit flat compared to the original (maybe a direct conversion was used).
Real bug: For some reason I am asked to enter my name for a high score after the attraction mode played a few times, and a score is recorded. That shouldn't happen.
While the music is intact, it sounds a flatter than I remember it, but no big deal. Some of it bleeds into the sound effects I feel. Wonder if that can be adjusted. Some of the sound effects go on for longer than they should, and turn into a permanent beep of sorrts, like the thowing ball. The sound effects themselves here don't have that clarity, loudness/crispness here, they used to be kinda funky and playful on the CPC. The bonus life and new life effects even had a sort of "echo" to them. The strawberry too, when it was smushed. No sound for anything being smushed in this, yet, I believe. It might be difficult to replicate these on a SID, might not be, I do not know.
I'm really looking forward to the future of this version.
I believe the original author passed away? I vividly remember seeing a web page he designed over 20 years ago, where he talked about this game.
PS: I should read more. Like the text on the page. My apologies, I understand how it was made now. :) Anyhow I hope my points here are still alright to be made and I appreciate all the work!!