Factual error: The drug-runners at the start of the film mention that their scheme is to smuggle cocaine by mixing it with molten plastic, molding the plastic into dolls, shipping them and then re-melting the plastic to separate the cocaine again, which will leave it "100% pure." While you can indeed smuggle cocaine by mixing it with plastic, the process to recover it is way more intricate than simply re-melting the plastic, and requires chemists to treat the plastic with all sorts of chemicals and compounds in a complex process (and it will not be "100% pure" as suggested), and it is usually done with larger plastic objects (like plastic dog-houses or car-parts), as something the size of a doll isn't going to be able to hold all that much cocaine.
Revealing mistake: During the nighttime forest fight-scene, when the Zoanoid rips the tree out of the ground, it's obviously a lightweight prop. Furthermore, when he starts trying to swing it at the Guyver, both ends of the tree are broken off cleanly... which doesn't make sense since the top half should be covered in branches and whatnot.
Trivia: The first live-action "Guyver" movie had notably tame (often cartoonish) violence and a greater focus on broad comedy in comparison to the darker and gorier Manga and Anime franchise that inspired it, causing some backlash from fans. For the sequel, returning director Steve Wang made an effort to deliver a film tonally closer to the original source materials, and thus added in harsher violence, added significantly more blood to the fight scenes and removed many of the more comedic elements from the first film.
Trivia: Does the main character Shawn seem familiar but you can't place him? That's because he's actually played in this film by famed voice-actor and screenwriter David Hayter. He's notable for many voice-only roles, including playing the main character in the first four "Metal Gear Solid" games, and also worked as a screenwriter on some blockbuster films including the first two "X-Men" movies and the popular "Mummy" spin-off "The Scorpion King."