I'm glad this was made... maybe TOO glad.
I try not to get so uptight about things like this, but one of the reasons I'm glad this crossover came out, is because I've got vague memories of an unfair criticism of Jimmy Neutron simply being a CGI version of Timmy Turner, and that simply not the case.
Jimmy Neutron is convinced that everything in the universe can be explained and solved with rational common sense and scientific know-how. Timmy Turner is a hapless victim of cruel fate, trapped in a childhood of seemingly endless despair, even though he wants the kind of childhood he can enjoy like he thinks other kids have. Both characters couldn't possibly have anything in common.