A relatively niche and outsider genre. Related to synthwave and vapourwave, but distinct from both. It stems from CIS countries which emerged out of the 1991 collapse of the Soviet Union.
Tunes of this genre are slower-paced than synthwave, closer to chillwave or dreamwave, and have a 1980s influence present, alongside reduced bass and an aim for a more specific sound compared to other genres. Frequently, Sovietwave tracks also have excerpts spliced in. These excerpts come from a variety of sources, but chiefly they come from Soviet politicians' speeches, popular radio and TV shows, or Soviet cartoons. The aim of such excerpts is strictly to increase the nostalgia factor of such tunes, evoking a sense of a lost dream of spaceflight, a utopian Soviet society, or Soviet futurism in general, and not to send a pro-Communist/Soviet political message.
I came into Sovietwave expecting Soviet propaganda, but left with something else than Soviet propaganda - something much better.
(note - edited to provide a more accurate definition of what Sovietwave actually is)