Pete Hammond of "Boxoffice" called "Igor" "first rate" for a low-budget film, while the movie's look was considered by Demetrius to be its best aspect. Some sources thought the film was "all its own" and "fresh" in spite of its influences of Tim Burton films and old-school horror movies, "The Orlando Sentinel" labeling the animation a "credible" rip-off of "The Nightmare Before Christmas" (1993). "The A.V. Club" stated the visuals succeeded in "detail and fluidity" if not for taking "advantage of three-dimensional space." One critic highlighted the film's use of shadow, "not only to strike the pre-requisite mad scientist mood but to enhance the feeling of 3 dimensions. This, coupled with a cinematic eye leaning towards the dramatic, further pulls you into the feature, exposing the creator's love for black and white horror films of years past." The visuals did have its detractors, however. Schager wrote the animation is "at times is vibrant and elaborately eerie, and at others is so stiff, inexpressive and flat." "IGN" thought the animation looked like "a bargain-basement ripoff of better films." Franklin called it too "inconsistent," Hartlaub who opined "the character design leans more toward disturbing than cute," and "Total Film" who was turned off by the "shoddiness" of the art style. The voice cast was heavily praised, being called "stellar," "top-notch," and a "quirky highlight" in reviews. According to one journalist, "this is one cast that consistently had me laughing across the board."