A great creature feature will generally have compelling moments of dramatic tension and personal interactivity to drive up the character development, making you care about the people who spend the majority of the movie facing up against the big bad. Itsy Bitsy goes the other way on that, it injects a couple moments of big spider to break up the uncomfortable family drama. This works... less... good.
Still better than 90% of the "a giant (x animal) is coming for you" movies.
Final rating:★★½ - Had a lot that appealed to me, didn’t quite work as a whole.