- Crowning Music of Awesome: The movie's opening theme.
- Hilarious in Hindsight: An agent of Intersect named Casey?
- Germans Love David Hasselhoff: Apparently Gemini Man was more popular in England than it ever was in America. Unlike the US, they actually aired all eleven episodes, released a record album, and even released one issue of its own annual.
- Narm: "This can't BE?! You're DEAD?!"
- "Optical illusionnnn-uh!"
- "I wonder what happened to Abby. She's some gal."
- "Hold it hold hold it Sam."
- "Now waaaaaaaait a minute you two..."
- "Dynamite! This here fist packs sheer dynamite! WA-HOOO!!"
- "You're as elusive as Robert Denby!"
- "Leonard, I hear you've grown quite a mustache while I was on vacation."
- "I'm going to start to work on my patent applications."
- "I'm working on my patent papers, and I really would appreciate it if you wouldn't disturb me."
- "Be careful, Sam!" "Give it the old college try!"
- The Scrappy: Buffalo Bill.
- Special Effects Failure: One of the best scenes is when Casey, holding a gun, punches out a mook standing four feet away without causing the revolver floating in the air to so much as wiggle.
- What an Idiot: All things considered, Casey is a pretty lousy secret agent. He totally hangs on every word by Dr. Hale, allowing him to switch himself out of the truck and Abby into the truck, does not notify his superiors when he finally catches on to Hale's absence, blatantly and non-subtly asks Buffalo about Denby's activities while surrounded by other people that easily could have been working for Denby (and one of them was!), tells Buffalo he's a secret agent (thus allowing Buffalo to tell Denby)...it's a wonder the guy hasn't been kicked out yet, invisible or not.
- Leonard Driscoll's plan to transport the tripolydine? Sending one agent in a truck while an actual military convoy is used as a decoy. In other words, this super secret fuel additive and everything related to it is being dispatched largely unguarded...which is of course exactly what the fraudulent Dr. Hale was planning for in the first place. Had they sent real military protection, Dr. Hale wouldn't have been able to get away with it.
YMMV / Gemini Man