Honestly, I can say that I really enjoyed this film. The acting is great, and the story overall of a man struggling with schizophrenia is an emotional one. However, I fail to see why it was marketed as a comedy, as while it does contain some scenes of dark humour (mostly scenes involving Jerry's cat, Mr Whiskers) I would have marked it as either a drama or thriller.
Slight spoilers below
The overall story follows Jerry (played by Ryan Reynolds) and his job at Milton Enterprise, where he falls for his coworker, Fiona. At first glance, Jerry seems like the typical working man, but unfortunately, he suffers from schizophrenia, which causes him to hear his dog, Bosko, and his cat, Mr Whiskers, talk to him and give him advice on how he should live his life. The story goes on to show how Jerry feels alone without the voices of his pets to guide him, and how ultimately, even with good intentions, he manages to acidentally kill Fiona and his coworkers. T The film ends bittersweetly, with a slightly confusing ending where it's left up to interpretation whether Jerry is actually living out that scene, or having another hallucination.