When Hebe stabs her self, the knife/dagger is under her armpit before the shot changes to the knife in her shoulder.
At the beginning of the cave fight Sotiris and Hercules only have swords. As soon as they form a shield wall they have spears.
When Hercules uses his lightning sword to kill the mercenary fighters the dead bodies change between shots as he walks among them
When Hercules enters the palace to kill the king it is raining heavily outside, but when he opens the door, dried leaves blow in from behind him.
Sotiris asks for 20 men to secure the passage. More than 20 march with him. Before the fight scene the numbers keep switching in there formation to 17-18 men. Finally they were at 20 once they formed the shield wall.
During the fly-over the wall in the beginning, the arrows appear out of nowhere in the soldier's hands, as they pulled back on the bows.
It's a well known fact that all arrows in movies are CGI. Can't very well have real arrows flying around the sets.
When Hebe is riding her horse away from the Greek soldiers and turns her head. It is obviously green screen as her shadow appears from the background.
At the one hour mark, where Hercules fights four soldiers to defend an elderly villager, one of these soldiers can be seen wearing tennis shoes. Bright green tread is clearly visible when the first soldier gets back up after the double clothesline.
During the battle of Horus' Pass, Hercules (or commander Sotyris) order "Testudo", a command in plain Latin (characters are Greeks), used by Roman legions, centuries after the events in this movie..
The necklace Hebe gives Hercules includes a spring ring clasp, which was not invented until the early 1900s.
The Ancient Greeks held athletic contests, but not gladiatorial games. Gladiators originated on the Italian peninsula around 700 years after the settings for this movie.
Stirrups were not invented for many centuries after the time period this film attempts to portray. Certainly the ancient Greeks did not use them. However, they are seen in the opening battle and throughout the rest of the movie.
Rail slider track is visible in the scene when Hercules and Sotiris are tied back to back.
In the final battle Hercules is wearing the cloak made from the hide of the Nemean lion. This cloak was last seen in the possession of Iphicles and there is no scene explaining how Hercules got it.