I had a problem with my sound looping during cutscenes but working perfectly fine ingame, I noticed other ppl had this problem aswell but didnt get much help, keep in mind however i purchased my game via steam so not sure if that has anything to do with it,

anyways after some research I found a possible/temporary fix that simply involves replacing the bink file in the minininjas directory with that of one from another game, For example I used the binkw32.dll from my portal directory which didnt have any sound problems during its cutscenes, and now my mini ninja cutscenes are working just fine, i would advise you backup your original binkw32.dll file first tho incase this doesnt help.

Now you can play this amazing game the way it was meant to be played, hope this helps.