Changes
/* Attribute based Sprites and Animation */
Such games had no smooth movement of sprites. You moved the sprite "character per character".
As such the sprites are unmasked, being not really more than tiles-mapping... This means the sprites must actually fill the characters or you get the unmasked character's corner artefacts.
This was a "good" other way to get rid of Attributes Clashes and having actual "colours" on ZX Spectrum. But some speccy ports were then emulating the attribute system... which can be quite bad because CPC in Mode1 has Half colours the Speccy has.
*R-Type.
*Space gun : this game being quite late in CPC era... it is not really good and was probably rushed to the release. Yet the Character based engine enables "enormous sprites", but lacks the smooth movement.
Such technic was actually used for quite a good amount of Mode0 games... This is not "Speccy port" speccyfic (Pun!) but it is good to have it mentionned, as a common game design technic for both machines.