In Ender's first team, in several different sequences during the movie when the team is at attention, the blonde girl on the left side and the black girl on the right side appear and reappear within the same scene.
When the launchies are introduced to the Zero-G battle room, Ender and Bean ponder how to orient themselves in the environment. Ender makes observation to designate the enemy's gate as "down". However, the launchies aren't yet privy to the specifics, rules, or environment of the game until Dap tells them afterwards, so there is no way for Ender to know about the designation of the gates yet.
When Ender and the others are launched into space to go to Battle School, huge clouds are shown (very realistically) moving outward from the launch area as the ship rises, similar to scenes of the Space Shuttle or the Apollo Saturn V taking off. This isn't exhaust from the rocket; in order to prevent (mostly acoustic) damage to the trench underneath the rocket, thousands of gallons of water are poured into the trench, and this is turned into clouds of steam by the rocket's engines.
However in the film, the rocket is seen to be tilted into a vertical position above a large circular opening into which the engines will fire. There is nowhere for a water deluge to pour, or really any need for it.
The launch acceleration is much too high. It appears to be about 6g, which would probably have caused a number of the cadets to black out. The Saturn V that launched the Apollo astronauts reached a very brief peak acceleration of 4g with the 1st stage. The other stages didn't produce more than 2g (stage 2) or 0.75g (stage 3).
When Ender is assigned to the Salamander Army and he arrives, the Army members are playing baseball on the floor. If Ender catch the ball it is is clearly visible, that the ball is not even thrown and the batter hit nothing, just waving the bat. Ender has already the ball in his hand and just mitigate, that he catch it.
Ender is told that Petra had been "trained to fire" the M.D. 500. However, when it is actually used she simply presses a button. Not only this, but she only presses it when given the commands "Go for the center" and "Fire now!" by Ender. Hardly a skilled job needing a specially chosen and life-long trained child. Ender could even have pressed the button himself, thus making her job redundant.
Ender says to Stilson, "One on one, then why are your buddies holding me?" Just before he starts talking he moves his lips, clearly saying something, but no sound is heard.
When Bonzo is marching with the Salamander army and his cadence as they march to the game... when he gets onto the platform it is clearly visible that he is still singing the cadence but his lips do not move.
Colonel Graff remarks that Napoléon Bonaparte "conquered the known world," which is not untrue. The correct reference should have been Alexander the Great who, it could be said, conquered the known world. This could be accepted as accurate because he did conquer the parts of the world of which Macedonia and nearby regions had knowledge. The wilds of the Far East and of western and norther Europe, as well as central and southern Africa were the stuff of little more than rumor.