George Romero has directed some pretty interesting films that do not have the word "dead" in the title, and even though it falters mostly in the second act, I would still count "The Dark Half" as one of them. There are a lot of interesting ideas here courtesy of the Stephen King novel that this is based on, and Romero translates them well to the film with his smart screenplay. Some work better than others, however.
The idea of an alter-ego being born out of one twin being absorbed by the other one during gestation is fascinating and leads to a ghastly and memorable opening to the picture, but the ever-present sparrows being a symbol of transporting one's soul to the next life seems silly and unconvincing. It's a mixed bag, as is the film itself.
The second half drags, and the whole thing feels about a half hour longer that it really needed to be. Timothy Hutton is generic and genial enough to portray a sympathetic lead character, but he doesn't have what it takes to play that alter ego of George Stark convincingly. The death scenes here that require him to be pure evil do not carry much weight. However, Michael Rooker is quite good in a supporting role. I'm fairly certain that the film would have been a lot better had him and Hutton switched roles. Rooker definitely has what it takes to be menacing.
The film itself is beautifully shot by Romero, but the story isn't involving enough to hold your interest. The book was solid, but as a movie, "The Dark Half" shows a lot of promise early on but there's not enough to sustain it for the entire run time. You simply cannot fault the director, but a lot of the novel's weightier themes are definitely lost in translation.