- Alas, Poor Scrappy: Even those who thought Shane was The Scrappy (on account of being such a massive Jerkass) and were hoping for his inevitable death thought that the way he died redeemed him.
- Alternative Character Interpretation: Is Henry an obsessive, deranged psychopath, or a misguided, mentally ill person who just needs a little love?
- Is Shane just a Jerkass by nature, or does he have some Freudian Excuse the rest of the island doesn't know about?
- Did Chloe care as much about Cal as she said, or was she just glad to have a man so devoted to her she could get away with anything?
- Considering she killed herself after Cal died, it seems pretty likely she genuinely loved him.
- Did Malcolm ever feel guilt about what happened to Booth, or was he just afraid he would be found out?
- Was Hunter trying to break up the wedding for Mr. Wellington's money, or was he really in love with Trish all along?
- Did Katherine love Thomas as much as she said she did, or was she a bored trophy wife looking for some excitement?
- Likewise, did Richard love Shea or Madison at all, or was he just married to her for the Wellington money?
- Is Maggie a sweet old lady who just wants to make Trish and Henry's dreams come true, or is she a greedy Dirty Coward who got what was coming to her?
- Was Nikki really as much of a badass as she claimed, or was she just as frightened and helpless as all the others?
- Awesome Music: "Letters from the Sky" by Civil Twilight, during Cal and Chloe's death scene.
- Big-Lipped Alligator Moment
- Cousin Ben's death is shown in the first scene of the pilot and he's barely mentioned again.
- Cal's violent tendencies were hinted at in the official bios, but only displayed once when he dunked Chloe's head in the water in Episode 1. They are never mentioned again, and Cal is devoted to Chloe for the rest of the series.
- Base-Breaking Character: There's actually a fair amount:
- Abby Mills and Jimmy Mance, mainly between fans who thought the two were very cute, endearing, and likeable vs. those who found them bland and uninteresting. Being fairly predictable survivors and living over more developed and arguably more interesting characters does not help, and neither do Abby's numerous Too Dumb to Live moments.
- Shane Pierce. Some fans liked his redemption storyline and found him to be hilariously douchey, particularly towards the end of the show. Others found him to be an unbearable, unlikeable Jerkass who deserved to die. Though even most in the latter group felt sympathetic towards him when he pulled his Heroic Sacrifice (see Alas, Poor Scrappy above).
- Malcolm, with it mainly coming down to whether or not people liked the money subplot.
- Broken Base: The decision to have Wakefield be alive and one of the killers. It was either a predictable and lazy way to explain most of the murders, or a satisfying way to reveal the identity of the second killer.
- Complete Monster: John Wakefield is a legendary killer from Harper Island's past who was thought to be dead, only to resurface and continue killing. The former lover of Sarah Mills, he was abusive to her, leading Sarah to ask for help from Sheriff Charlie Mills, who had Wakefield arrested on false charges. Let out of prison for good behavior, Wakefield returned to the island, where he killed 6 people, including Sarah, only to be shot by Charlie and fall off a cliff. Surviving, Wakefield went into hiding, and met up with his illegitimate son Henry Dunn years later, to train him as a killer. At the start of the series, the father and son duo plan to lure out Henry's friends and family, including Charlie and his daughter Abbie, into Harper's Island, where both of them would kill everyone. Lurking in the shadows, Wakefield secretly killed many of the victims, and set up a warning to manipulate and scare the group. He would mutilate many of the bodies, subject his victims to painful deaths like burning alive and sawing in half, and was willing to try attacking children. By the end of the series, he and his son manage to kill the majority of the cast, and left Harper's Island desolated before John gets betrayed by Henry. John Wakefield's action made him a legend, an infamous serial killer single-handily responsible for Harper's Island's infamously dark and bloodstained past.
- Draco in Leather Pants: Henry has been getting this a lot, creepily enough.
- Ensemble Dark Horse: Due to the large cast but very narrow character focus just about everyone is this.
- Sully is probably the most popular character on the show, on account of having the most Character Development, a well written redemption arc, and his Jerk with a Heart of Gold status.
- Of the main characters, Chloe and Cal tend to be amongst the most popular for their overall cuteness as a couple and being the Plucky Comic Relief.
- Uncle Marty's delight in being the Life of the Party makes him a joy to watch.
- Chloe's fellow bridesmaids Beth and Lucy are also pretty well-liked due to Beth's Single Woman Seeks Good Man moments and ultimate woobie status and Lucy's love for her dog and surprisingly insightful conversation with Trish.
- Danny's pretty popular for his fighting skills, and loyalty to his friends.
- Nikki has a surprising amount of depth and charm for a Flat Character, something the fans certainly appreciate.
- Booth's nature as an attractive nerd and a Butt-Monkey wins him more fans than his small role would lead you to expect.
- Epileptic Trees: Amongst some truly bizarre theories, there was a widespread belief that Booth was alive and the killer until the producers openly refuted it.
- Booth actually being shot by one of the killers is also a theory.
- Fan-Preferred Couple:
- Due to Malcolm's Scrappy status, lots of fans ship Beth/Danny.
- Malcolm/Booth, probably derived from Malcolm's breakdown after shooting Booth.
- Fan-Preferred Cut Content:
- Pretty much everyone agrees that the deleted scenes where Malcom and Beth interact in "Crackle" are pretty good and should have been kept. They give Ensemble Dark Horse Beth perhaps her only real moment in the spotlight and are decently cute and funny.
- Katherine and Thomas's Deleted Scene in "Ka-Blam" also has many fans who mourn its deletion. It resolves the Plot Hole about Thomas's change in attitude toward Hunter and develops Thomas and Katherine's relationship when they barely converse outside of that scene.
- Fanon:
- Ask the fan base and you'll find that Abby was unconscious for three days, Henry meant for JD to survive locked up in the jail cell and Henry deliberately gave his middle initial as "W" on the wedding invitations to stand for "Wakefield" (his middle name is established as "James" in episode 13), despite this last one being a production error.
- The fans have also dubbed Abby's full name "Abigail", Katherine's maiden name "Shepherd", Beth's full name "Elizabeth", and Maggie's full name "Margaret".
- A lot of fans insist that Henry was solely responsible for Thomas Wellington's death, mainly because he apologizes to Trish when she accuses him of killing Thomas and JD. While he almost certainly did kill JD, the only other murders he cops to committing on his own are Reverend Fain, Richard and Katherine, and there's nothing to suggest that Wakefield wasn't involved with Thomas' death like he was almost all the others.
- He's Just Hiding: Lucy can inspire this due to still being alive (albeit on fire) when last seen on camera, and no one ever coming across the body.
- Hilarious in Hindsight: In one of the early episodes, Henry and the groomsmen are entertained by a stripper. Henry is embarrassed by the fact that it's his friend's little sister, which is awkward. Sully says "that's what makes it dirty". In the last episode, Henry is declaring his undying love for... his own little sister.
- Memetic Mutation: Among fans: "Who the hell is Beth?!"
- Uncle Marty is the coolest dude in existence.
- "Gigi is people!"
- "It's gonna be okay!" or some variation thereof.
- Moe: Bridesmaids Beth and Lucy spend most of their screen time being endearing. For Lucy, it mainly manifests in her doting on her Canine Companion and acting as a confidant for Trish. For Beth, it's her implied shyness and cute flirtations with the schlubby Malcom, even if most of that only takes place in Deleted Scenes.
- Moral Event Horizon: In retrospect, this happened in Gurgle when Henry kept Beth, Danny, Sully Cal and Chloe from leaving for the ferry to help look for Madison. By doing so, he doomed them to die when them leaving wouldn’t have hurt his plan at all, they’d all been good friends to him -although he did have a grudge against Sully- and he saw how scared and unnerved they already were by everything that had happened.
- Narm: This series contains comedy deaths, after comedy deaths, after comedy deaths.
- Shane is just written as so unrealistically mean, especially in the second episode, that it is hard not to laugh at his lines.
Shane: "Boohoo, John Wakefield killed my mommy! Get over it! Now Get out, I gotta pee!"- Madison's scenes where she is supposed to be ominous and creepy would have worked if the actress was a few years younger, but instead she just ended up looking... a little silly.
- The first third of the show before the murders are discovered contains an absurdly high number of Cat Scares, especially episode one.
- Nightmare Fuel: What turns out to be the reason all of it happens? Henry killing everyone because of a promise Abby made when they were kids? And then trying to hold her to it? Definite nightmare fuel for some people.
- One-Scene Wonder: Uncle Marty, despite getting killed off in the very first episode, is frequently a fan favorite.
- The Scrappy: Madison and her mother Shea. Incredibly, they both live because Executive Meddling stated that the writers couldn't kill a child or every member of her family.
- She Really Can Act: Katie Cassidy's performance as Trish was well-received, after several past roles which received less favorable attention.
- Slow-Paced Beginning: The first four episodes are quite a slog through an extended Developing Doomed Characters. Then everyone finally realizes that people are being killed and things pick up considerably. Note that for the people watching at the time, this meant spending an entire month waiting for these people to get their asses in gear. This wound up sealing the series' fate: The first three episodes averaged over seven million viewers, but dropped below five million for episode 4 and never recovered, ending in a cancellation after the season finished.
- Special Effect Failure: Henry's death. After a huge number of well-executed death scenes with convincing blood and gore, it seems a shame that the very last of them failed to actually create a convincing impalement effect. It's painfully clear from the awkward angle that for the shot with the blade protruding from his back, it just held under his arm, not stuck in his chest.
- Tear Jerker: Sure, it's a murder mystery and there's enough death to go around, but you have to admit you hated the killer a little more when Cal and Chloe died.
- They Wasted a Perfectly Good Character: There's probably someone out there who'd argue the case for any given character at one point.
- Cole. Plenty of interesting characters died at their peak, but he takes the cake.
- Sully as the episode before his death seem to set him up to do something great, and instead he's murdered early on when he could have been a focus of the episode.
- Lucy and Kelly die in the second episode after getting some nice focus and plot involvement which could have at least been drawn out. Killing one for the episode's death toll might have been necesary, but both feels like overkill.
- Nikki, as her status as Abby and Henry's old friend doesn't get as much focus as it could have.
- Beth is a deeply liked character who many fans wish had spent less time in the background.
- Clueless Deputy Lillis could have had some arc or importance in the second half of the season Instead he vanishes for several episodes and then is Killed Offscreen.
- The Woobie:
- JD is a genuine one. A mentally-troubled and bullied loner whose parents died in the back story, who everyone thinks is dangerous and who is blamed for all the murders. He is finally killed by his adoptive brother Henry and refuses to speak to protect Abby. Word of God says Henry murdered their parents too.
- Kelly is another. Loses her mother in the 2001 murder spree, suffers abusive boyfriend Shane and sees John Wakefield alive. No one believes her, which is how he gets away with it for a long time. She is hanged by him before anyone realizes she wasn't mad.
- Trish is one as well. Not only does she watch her dad die horribly in front of her, but in the end, she's murdered by the one man she loved the most and trusted with her life after he used their entire engagement as a means to get a different girl to fall in love with him.
- Beth is fairly pitiable by the end due to her Innocent Bystander status and desperate, nerve-wracking desire to get off the island, and her crush Malcom getting killed.
