Have you been contusioned during a fight with a squirrel?
I told how it sounds.You don't need to know what it means,just judge by ear how it sounds.For me czech sounds very similar to serbian.I don't know serbian but I suppose they have certain similarities.
The Czechs and Poles tend to cut the vowels while Russians say them.For example nazdravi in czech nazdarovie in russian.Divka in czech,debushka in russian.Krasna in czech krassivaya in russian.The Poles tend to keep several of the vowels but they add some sounds like cz,sz which add consonants thus making the language sound again syncopated but more rounded than czech.Because if you don't have vowels where will the ton be?So while russian is melodic and flows,czech has twistes and pauses and polish ups and downs in intonations with several endings to cause again more smooth sounding sentences.
Anyway I am not an expert in slavic languages,this is my opinion after listening to them.