R-Type is the greatest game ever made, right? Right? No? Then get off my land, you pervert. It just is.
The 8-bit ports of the game were mixed: the Amstrad got a terrible, slow, drab port. The C64 got a fun shooter that felt loosely based on the source, but which loses points for straight up doing it's own thing (as the C64 often did).
But it's the ZX Spectrum port that really shines. More colourful than it had right to be, fast, faithful, fun. It was a weird kind of miracle: so accurate you could even use your arcade learnings to do well at the game.
So, for the 8-bit micros at least, clear Speccy win!
...
But they were, all of them, deceived, for there was another 8-bit computer R-Type made.
On the internet, in the coding forums, homebrew coders forged in secret an Amstrad port to beat all the others. And into this port they poured colour, accuracy, music...
And the result is pretty great. Amazing to see what the Amstrad can really do when it isn't getting stinky Spectrum ports. I would say this one ties with the Spectrum port for playability.
I mean, the arcade is clearly the best version... (if you're talking the original game).
For the ports... the Spectrum is great for sheer chutzpah, but the PC Engine port is probably the most faithful of all the versions that weren't running an emulator. The Sega Mastersystem is also extremely good, on much less powerful hardware.