Some very impressive homebrew fighting games has been released for the ZX Spectrum. Many of them can easily compete with the best ones from the commercial era. Be sure to also check out the honourable mentions.
Huge playlist archive with lots of similar videos:
00:00 Intro screen
00:03 1996 Mortal Kombat:
03:10 2013 Renegade :
06:09 2015 Target Renegade :
09:15 2016 Fist-Ro Fighter:
12:18 2018 Mister Kung-Fu:
15:20 2018 Ninja Gaiden Shadow Warriors:
18:22 2018 Mighty Final Fight:
21:28 2021 Angels:
Honourable mentions:
Great games, but not 100%