Metropolis is preserved - it is just missing from Dilwyn's site.
I assume it is freeware along with the rest of the Medic titles by Janko Mrsic Flogel .... but possibly was not made freeware, as Janko re-published Metropolis, with slightly different graphics as Citadel (sold by Eidersoft).
If someone can get Janko to respond to emails about his software now that he is interested in the ZX Spectrum Vega project - it might be possible he can give his consent now to all of his software being freeware...