The first Lego super hero animation I saw was terrific. It was witty, funny, had a great script and was very well done. This one... not so much. It's not witty, not charming, just very mediocre. The upside was the relationship between Black Widow and her father, which is a decent enough morality story for kids. But it's a long story for one point: everyone is imperfect, and everyone changes. Thanks for that sparkling wisdom, but it doesn't equate to the foundation for an entire film.
What stood out to me most of all in this entire film is how odd Lego character heads look without a hat or hair. They have this "chimney" coming out the top of their heads. When that oddity stands out more than the film itself, that's not an indication they made a good movie. Kids might like it, but I'm thinking even they would only watch it once.
So not funny, not witty, not Lego. Three bricks short of a finished project.