If you're looking for body count, blood, or bogeymen, this film is not for you. It is more of a psychological thriller than a horror film, though it was billed as horror, likely because of the pseudo-science gimmick that provides the basis for the conflict in the plot.
While the film tends to wander a bit (i.e. a sub-plot involving the research head that gets dropped 3/4 of the way through) it stays fairly well focused on the main character and his problems. Aside from the lead, the most effective acting was done by the monkey(s), but the "real" actors do a pretty good job of carrying their own. It gives you a little insight into what it's like to be quadriplegic. For a late 80's movie, the style of filming was well done, there is very little cheese, and the special effects didn't overreach.
The premise seems a bit farfetched to our currently more sophisticated and informed sense of what's possible on the genetic engineering front. After all, this movie was made 15 years ago. If Romero had gone with either a supernatural cause or a plain animal jealousy angle, it might be less dated, but then again it might have been a little less believable to begin with.
Not very horrific, not startling or scary, but worth seeing if you don't mind a slightly slow-paced thriller. I gave it a higher than average score (6 out of 10) just because it didn't make me say "oh, please!" too many times unlike other movies from that time--particularly horror films--are prone to do. For example, the pivotal moment is fully supported by plausible input earlier in the film, it's not one of those miraculous developments pulled out of nowhere in the last few seconds before the climax.
