The play received 'mixed' reviews. = The play's reviews were 'mixed'. [=some critics liked the play, while other critics did not]
I accidentally 'mixed up' the two files. [=I put each of the files in the place where the other one should have gone]
He 'got mixed up in' a plan to destroy the government. [=he became involved in a plan to destroy the government]
(..) - I don't feel that way. - A lot of details never came out. - Yeah, well, good luck. Come on. You're like everybody else. You think too much, you get mixed up. - You know what I mean? - I don't think you have any right to... Loudmouth. Look at that come down, will ya? You know, this reminds me (..)1957 12 Angry Men
(..) Perhaps if the gentleman down there who is disagreeing with us could tell us why. Tell us what you're thinking. We might be able to show you where you're mixed up. Maybe this is an idea. It seems to me that it's up to us to convince this gentleman that he's wrong and we're right. Maybe if (..)1957 12 Angry Men