- The gameplay is probably one of the most-complained about flaws, but it's there for what it represents, not for how enjoyable it is. As Hardcore Gaming 101 pointed out, Americans love freedom. That's why they formed their own nation, and that's why they prefer cars to public transport; cars can go on any road, while public transport follows predetermined routes, and you only occasionally need to change direction to get to your destination. However, in Japan, people use public transport all the time, and cars aren't a central part of the lifestyle. This is also reflected in Role Playing Games: while America makes open-world RPGs, Japan makes linear story-driven RPGs. A major theme of the game is how cultures often try to force themselves onto each other, so the gameplay serves as a reverse of the storyline - rather than America forcing democracy onto Japan and Japan wanting to nuke them in revenge, Japan forces linear paths onto Americans and Americans get pissed off about it. Kind of like how people got annoyed by Liquid possessing Ocelot in Metal Gear Solid 2: they both represented a villain for Snake to defeat, but possession didn't really make sense in the context of the MGS universe.
- The title of Target 01 is "Sunset". Its events describe the potential destruction of Japan, the Land of the Rising Sun.
- The mahjong scene in "Sunset" seems to be little more than the diplomats killing each other over one of them cheating (and the person who did it seemed to not realize it), but it makes more sense when one keeps in mind that they were supposed to be discussing whether to stop Japan's demise. The whole scene is another political metaphor: "one false move can destroy entire nations".
- Why does Con use a Gangsta Style while pointing his guns and perform a Precision F-Strike when he gets a critical hit? In "Hand in killer7", Con is described as being close to Coyote. Coyote nearly holds his gun upside-down when shooting, and he hisses a "You're fucked!" whenever he lands a critical hit. Con is copying Coyote's mannerisms.
- Why the Art Shift in the Cloudman and Alter Ego chapters, and specifically only those chapters? A central theme in both of those chapters is the relationship between media and reality in different ways: Ulmeyda's company manages to be successful despite not actually producing anything simply because it has such appealing advertisement campaigns; and the events told in the Handsome Men comic book later come to pass in real life. Changing the medium through which the game communicates with the player helps highlight this theme.
- In Target 06: "Lion", Matsuoka could've fought or avoided Garcian (Kun Lan); or he could've defected and actively helped Garcian (Harman). Instead, he invokes Taking A Third Option and gives Garcian the chance to choose what will happen. At the same time, Garcian's choice is not part of Harman's or Kun Lan's plan; so the choice is completely his. That being said, it doesn't change the fact that the epilogue, set in Shanghai 100 years later, ends the same way as the end of Target 00: "Angel".
- Borders on Freeze-Frame Bonus, but if you rewatch the beginning of the Russian Roulette scene when Keane opens his revolver's cylinder, you can see its model does indeed have seven chambers.
- "Smile" Part 1 feature Harman and Kun Lan suddenly twitching and spasming in their seats after Garcian enters. Them the scene just ends. Come Part 2, and Harman and Kun Lan appear in the same situation...except an unseen Young Harman Smith enters the room and guns them both down, bodies twitching and spasming just like before. The scene ending at that point makes a lot more sense. Part 1's cutscene is some overt manner of echo of its counterpart in Part 2. As Kun Lan mentioned, "Time here [in the secret room accessed once at Garcian's home] is warped."
- Fridge Logic: The reticle that appears in first-person view looks vaguely like a peace sign. Ironic, given what killer7 is in both content and gameplay.
- killer7 has multiple parallels with its missions and the Cases from The Silver Case.
- #0: lunatics and Target 00: Angel are both Cold Open mission that serve as tutorials for their unusual gameplay.
- #1: decoyman and Target 01: Sunset set up what seems to be the main conflict.
- #2: spectrum and Target 02: Cloudman are Breather Episodes that follow decoyman and Sunset, respectively. They don't focus on the conflict previously set up, instead dealing with another issues in the world.
- #3: parade and Target 03: Encounter involve a character in the player's group confronting their pasts. (parade sees Sumio Kodai play his part in destroying the Yukimura Zaibatsu that ruined the lives of himself and his friends; while Encounter sees Dan Smith kill his mentor Curtis Blackburn.)
- #4: kamuidrome and Target 04: Alter Ego involve media being used for kidnappings and assassinations, respectively. kamuidrome hinges on the dark side of the Internet, Alter Ego on comics (and the Internet, to a lesser extent).
- #5: lifecut and Target 05: Smile bring the main conflict back into focus. In the process, most of the cast dies, and those who survive learn an Awful Truth.
- The epilogues purposefully do not elaborate on the previous reveals, and instead forge ahead to the ending.
- A great many design elements in the game are similar to television screens of the time (2005 in Real Life; the 2010's in the game's setting). The screen ripples and slides around when security cameras change Smiths suddenly (not to be confused with the player manually doing so from the menu), and when scanning for approaching Smiles. The small screen that shows up when the player reaches a junction is based on an function on old TVs. And whenever a cutscene or gameplay segment transitions from one or the other, the screen behaves as if it is changing television channels.
- During Smile Part 2, you can hear some static in the background. No, that's not the player's television or monitor or GameCube or PC acting up. That's there as a sign—that Garcian's multiple personality "system"—the multiple personas that the player can swap between, the various Remnant Psyches that the player can talk to—is falling apart.
- Related to above: Lion is absolutely deafening in what gameplay it lacks compared to the rest of the game: no Smiths/personas to play as, no Remnant Psyches/ghosts to talk to (unlike Smile, which still had that while losing the Smiths). There's virtually no wider interaction with the environment of Battleship Island, and what little there is is unlike what the player has experienced up to that point. The pivotal cutscene that involves your input is from the perspective of the one character you now play as. In Lion, you do not play as Garcian Smith of the killer7—you simply play as Emir Parkreiner, an assassin who has found his singular sense of self.
Fridge / killer7