Initially I planned on two topics for this: One called "The final barrier through the ages" or similar and another one for the Central Cavern, after a little thought a single topic seemed a bit better.
Anyway here are some comparison screenshots of both the Central Cavern and The Final Barrier from various platforms.
I do realise I have not covered all platforms here however there are some genuine reasons for this plus these are the relatively popular versions.
It is quite interesting to see the differences between them when they are directly placed next to each other. The actual game-playing image sizes do vary quite a bit so I have set them to be (within sensible proportions) similar, but not exactly the same resolutions as that would spoil the comparison effect.
The images displayed are in the following order: Amstrad CPC , ZX Spectrum , Oric Atmos , Commodore C16/+4 , BBC Micro , Einstein/MSX , Dragon 32 , Commodore 64 , IBM PC.