Viewers generally relish 'Insidious' for its thrilling horror and complex narrative involving astral dimensions and possession. The film is praised for its ability to instill genuine fear and its surprising plot twists, making it a favorite among horror enthusiasts. While the storyline and James Wan's direction receive accolades, some criticism is directed towards the less convincing CGI and monster designs, which some found underwhelming.

👍 Genuine fear and surprising twists

👎 Some CGI and monster designs may disappoint