I really enjoyed the movie for what it was! I can say they threw a little too much random comedy in and didn't fully solidify the plot until later. I was left questioning where the plot was heading a lot, but, it was still incredibly good. I loved getting to see Shaggy and Scooby getting some lime light! The few crossovers were nice, but, I would've preferred a more singular villain with more actual mystery and detective work involved. All in all, I can't really complain too much though! I really loved the animation, the plot (once it got to it) and the clever ending. They just need to chill on the modernized lingo and inserts because the movie will easily get dated. Also the randomness. Some random is okay, but a little too much can be distracting.
All in all I would watch again though! Great enjoyable movie.