There is a difference between horror and spine-tingling. Horror is when it's at its most hair-raising but on the other hand, spine-tingling is when it evokes just the SLIGHT feeling of apprehension. I guess it's a matter of degree so that apprehensiveness comes in at a lower level, which would make it more acceptable for those audiences who are faint at heart. Here it's where the fear is only hinted at, the best example being that scene where the state trooper leans a ladder against the cottage's roof, climbs it, and then slowly and apprehensively searches the roof with his flashlight.
The next morning, after he wakes up, he notices Giant-Fingerprints on his patrol-car! This is NOT horror but just awe to see the impossible and astonishing. What I enjoy about that scene is the Mixture of spine-tingling and wonderment. At the finale, that sense of wonder is confirmed when "The Fear" is found to be aliens from a flying saucer. So it's a unique MIXTURE of spine-tingling and wonderment.