Great, thanks a lot! I've got it now.
A couple of observations, though…
First of all, POKE 23658,8 turns on Caps Lock, if you wanted to insert this into the program (or into a short initial loader) so that players don't need to turn it on manually.
Also, I see no reason why this should be specified as being for Spectrum 128 BASIC. Given what it is, there's little chance that it needs any features that are exclusive to Spectrum 128 BASIC (i.e. use of a RAM disk or playing back music through the AY chip).
Moreover, by saying that this is for Spectrum 128s, it's likely that people will put the machine in 128 mode and use the inbuilt Tape Loader option to load the .tap file (you even advise them to do so in your loading instructions) – but if they do that, they'll find that they initially get a corrupted display that's quite distracting. That's because the 'Tape Loader' banner at the bottom of the screen doesn't get cleared (as there's no CLS command when the game starts) – so colourful artefacts from the banner remain on-screen until enough text has been printed to cause them to scroll off the top of the screen. But if you load the game in 48K mode, that doesn't happen because there's no 'Tape Loader' banner to get in the way.
So basically, I think you should drop all references to the Spectrum 128 and just state that it's for the Spectrum. There are still loads of 48K-only models in use, and as far as I can tell, this game will work just as well on them as on a 128K machine.
Overall, I'm pleased to see this game because it's interesting: you've taken a truly ancient computer game and ported it to a system that's merely extremely old! :-) – but one that's readily available to pretty much everybody, and still in widespread use, both natively and through emulation. So you've preserved this game in a practical way that makes it very accessible, and that's all to the good.
I'm not suggesting that you should have modernised the game for the Spectrum; that could certainly be done as a separate exercise, but the best initial step was to keep it as close to the original as possible, I think, and that's what you've done.
However, for the sake of convenience, you could potentially make it very slightly more accessible by turning on Caps Lock for the user with the POKE (even in a separate loader program, if you want to keep the main listing as authentic and unsullied as possible), and I really see no reason not to advertise it as being for all Spectrum models. NB The game is too large for a 16K Spectrum, but that's the only model it won't run on. And I very much doubt that anyone made any real use of a 16K Spectrum after about 1983 in any case!