The film inherits some of the shortcomings present in the brief comic it adapts, but also introduces its own problems while attempting to reach a feature-length running time and warrant a theatrical release. I suspect one reason for the largely unfavorable response to _The Killing Joke_ is that anticipation was extremely high beforehand. This wasn't entirely unwarranted, since it brings back Kevin Conroy and Mark Hamill in their well-known DC roles, and the comic itself is considered among the strongest stories ever released by the company. However, _The Killing Joke_ doesn’t live up to those expectations. Hamill delivers a strong performance, and generally, so does Conroy; there were moments where his portrayal faltered, though. It's unclear if he was out of practice or simply unengaged, but his vocal work isn't consistently perfect. The plot follows the narrative established in its source material, but instead of building on that story, they inserted a completely separate one at the beginning, creating a feeling of two distinct episodes from different series rather than a unified film. _The Killing Joke_ contains some unpleasant imagery and is not the revitalization of DC Animation many were hoping for. Nevertheless, the concluding scenes are excellent, and I'm not sure the movie warrants all the criticism it has received. Final rating:★★½ - There was much to appreciate, but ultimately it didn’t fully succeed.

Source on TMDB