- Acting for Two: The actor who plays Slick Dimitry is also one of the principle actors for Henry himself.
- All-Star Cast: In stark contrast with the original cast, the Japanese dub features many well-known Anime voice actors, including Mai Nakahara (Estelle), Hirofumi Nojima (Jimmy), Hiroki Takahashi (Akan) and Yoshito Yasuhara (Henry's father).
- Box Office Bomb: Despite grossing over 16 million dollars against a two million dollar budget, the movie is considered this by the studio, due to them buying the rights for over ten million dollars.
- Cast the Expert: The three mercenaries of Akan's who burst into the lab during the start of the film were played by actual Russian SWAT personnel, as Ilya Naishuller wanted the mercenaries to look believable for the first time the audience sees them.
- Fake Brit: Sharlto Copley is South African.
- Playing Against Type:
- Danila Kozlovsky, who's usually cast as heroic characters in Russian films, playing the gleefully psychotic Big Bad Akan.
- In the Japanese dub, Estelle is voiced by Mai Nakahara, a voice actress well known for voicing heroic roles, The Cutie or the Token Mini-Moe. Here, she voices the one of the members of the Big Bad Duumvirate.
- Tim Roth often plays antagonistic characters such as in The Incredible Hulk and The Hateful Eight. Here hes subverts that and plays Henrys loving father who gives him a motivational speech whilst dealing with bullies.
- Production Posse: Much of the film's crew was carried over from the Bad Motherfucker music video that Ilya Naishuller worked on before Hardcore Henry. Oleg Poddubnyy, who played the unnamed antagonist in the music video, is Akan's Dragon, Yuri.
- Throw It In: The scene where Henry accidentally knocks down a woman on a escalator during a foot chase wasn't planned. She was an extra who missed her mark and was genuinely knocked to the ground. When they stopped to check on her, she reportedly popped up and asked if they'd gotten the shot.
- Truth in Television: Akan claiming that a 100,000 baseball bats were sold in Russia compared to 50 baseballs actually has some truth to it. Russians actually purchase as many as 500,000 bats per year despite the sport being extremely rare.
- What Could Have Been:
- The film was originally titled Hardcore.
- The tone of the film was originally intended to be much more serious, but as the concept of a 90-minute long first-person action film was already asking a lot from audiences, it was decided to go with a much more off-beat and humorous tone.
- The scene where Henry finds a horse and attempts to ride it was originally planned to have Henry ride it out, only for the horse to be attacked by rabid dogs and Henry having to put it down. This was changed as western audiences weren't likely to have found it amusing.
- According to the Audio Commentary, Hippie Jimmy was originally going to be Biker Jimmy.
Trivia / Hardcore Henry