Some notes on brachypterous flies to look out for in UK/Europe can be seen in Dipterists Digest Vol 2, 1989 : https://dipterists.org.uk/digest

CHLOROPIDAE
Crassivenula brachyptera - found in pitfall traps in Suffolk heathlands

SPHAEROCERIDAE
Spelobia pseudonivalis - recorded from vole and mouse runs
Minilimosina gemella - taken in pitfall traps in upland localities but more recently, found in lowland too

EPHYDRIDAE
Nostima semialata - localities are calcareous/neutral short-turfed grassland

In this paper, it talks about Palearctic distribution of Nostima sp. There are only two species in Europe - N.picta and N.semialata and the paper keys N.semialata out partly on basis of brachyptery:

https://www.researchgate.net/publication/331512768_The_first_record_of_the_shore-fly_Nostima_semialata_Collin_1913_for_the_fauna_of_Russia

However, on Bugguide, there is an example of N.picta with reduced wings too, so perhaps good to check European obs against the other characters:

https://bugguide.net/node/view/1470270/bgimage