Remember that old episode of "The Simpsons", "Marge vs. the Monorail"? Remember how at the end there was a large escalator suspended in the middle of the air that would take people from the bottom, lift them up to the top, them send them to a horrible crash to the ground below? Well, "Harper's Island" was kind of like the Escalator to Nowhere; the first few episodes were kind of slow, but the pace soon began to pick up, only to have the series finally crash with the finale.
"Harper's Island" had it all : interesting premise, likable characters, decent acting, and creative murders. I have to say that the performances of Elaine Cassidy and Jim Beaver impressed me enough to interest me in seeing some of their other work. So where did this show go wrong? Let's sum it up to four reasons : inconsistencies, clichés, loose ends, and plot holes - most of which arise in the finale. These little tidbits help to tarnish - if not outright ruin - the series as a whole.
And let's not forget that a possible supernatural angle to the plot was introduced in the early episodes, but was abandoned abruptly about five episodes in. What was the point!?
"Harper's Island" is a mixed bag when you get right down to it; there's a lot to like about the first ten or eleven episodes, but after that prepare to be disappointed. I'd recommend watching the show only if you skip out on the last two episodes. On the other hand, if you choose to watch all the way through, don't say I didn't warn you.