7.8/10 for me.
I personally enjoyed this film, but I believe it would have been better to make another Scooby Doo! Mystery Incorporated season. I was really enjoying that show.
The animation was great, but Scooby Doo movies are supposed to be about the gang, and they barely did any of the mystery solving they should have done. Fred didn't even set traps... disappointing.
The voices were fine, but a bit inaccurate.