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]
(..) Roofilin. What the hell is a Roofilin? Wow. You are the world's shittiest drug dealer. Roofilin, for your information, is the date rape drug. You sold Alan roofies. Oh, shit. I must've mixed up the bag. My fault, Alan. Damn, Marsha's gonna be pissed off with me on that one. Whatever. (..)2009 The Hangover
(..) Roofilin? I sell no roofilin. Who gives a shit! Where is Doug? I am Doug. Your name's Doug?/ Yes, I'm Doug. His name's Doug too. Classic mixed up. Come on. Hey, Chow! You gave us the wrong Doug. Not my problem. Fuck that shit. Now you give us our grand back and take him with you. (..)2009 The Hangover