
Some time back, I wrote this about SCOOBY-DOO: "Perhaps the greatest mystery is how this certain trainwreck turned out to be a fun, enjoyable picture."
SD2, while not a trainwreck, is bigger, louder, and not nearly as much fun. It falls victim to the sequel's standard pitfall: it gives us more and more and more of the same, but it doesn't give us much to hook our imaginations.
Bummer.
PS My child laughed all the way through it, so YSMMV. (Your Spawn's Mileage May Vary.)