I'm using Retroarch with the caprice32 core, works perfectly fine from the beginning.
I had more problems with Curse of Trasmoz, but i've managed to emulate it with the fuse core, and remapping the necessary keyboard keys, to the Vita.
Bought the game on itch.io, played on my PS Vita, love it, bought the first one on itch.io, played it ony Vita too, loved that one too. The physical version of the first one will arrive in a few days, and i will buy the physical of this one, next month. :)
Never had a ZX Spectrum or Amstrad CPC, but i love these games and want the physicals in my shelf. Looking forward for the next one, to complete the trilogy, on a C64. ;)