Revealing mistake: When Project Applecore is first shown, a laser drill busts up some rocks. A forklift-like vehicle with a bulldozer front swoops by and picks up the rubble. Then the vehicle turns 90 degrees and heads away, but with none of its wheels ever turning. (00:05:20)
Revealing mistake: Dr. Murphy and another male worker at Project Applecore make fun of Lex Luthor and begin laughing at their own joke. As the guy laughs, one of the squares on the side of his hard hat does not move with the rest of him. His head, hat and the other squares bounce up and down as he laughs, but that one square stays put. (00:06:10)
Revealing mistake: When Tess walks into Lex's office, he is standing at his window looking out, or at his reflection. When he turns around and begins typing on a hand held device for the cure to Muscular Dystrophy, he at first only turns half way around, being 90 degrees and now facing parallel to the window. However, his reflection turns around 180 degrees and like he has his back to the window. (00:06:40)
Revealing mistake: When Doomsday slams Superman down into a hummer, watch closely. You can see that Superman has no face or hair. (00:18:55)
Revealing mistake: After Superman is thrown into a building, it cuts to Jimmy and Lois strapping themselves into a helicopter. The seatbelts in the chopper are not drawn correctly. The holes where they come out of the seat are not symmetrical, don't match from one seat to the next, and are overlapping the edges of the fabric on some and not on others. And then when it cuts to a side view of Lois, the holes are gone and it looks like the belt just stops at the seat. (00:19:10)
Revealing mistake: Doomsday drops Superman once he hears a little girl crying and walks up to her to try and smash her. As he is walking up, it shows a close up of the crying girl and she is wearing a pink shirt with denim overalls on. But look closely and you can see a mistake in how she was drawn. The straps of the overalls are incomplete and stop a few centimeters away from the buttons on them that are supposed to hold the straps in place, and the buttons are between the straps and her overalls, with a gap between the buttons and the front part as well. It's not connected at all and should be falling off her. (00:25:15)
Revealing mistake: An electronics shop has TVs on display, all showing a newscast about rising crime rates in Metropolis since Superman's death, and the window is broken by a brick as some thugs start stealing the TVs. Watch closely as they pull them out, the TVs have no power cords, but are on. Most noticeably on the second one when the guy has the TV lifted up, no cord seen, and yet the image still displays on the TV until he pulls it out of the window. (00:33:05)
Revealing mistake: When Lois looks in the driver seat of the bus, there is a mechanical doll there that turns its face towards her and holds up a kitchen knife. The doll has a missing eye, and this is shown in the reflection on the knife. But the crack that is under the hole where the eye is missing is not fully reflected. (00:36:20)
Revealing mistake: As Lex is walking away from the container that holds Superman's body, the glass of the container is reflected in the floor, as is Superman's body. But the little pedestal that he is hovering above is not reflected. (00:43:30)
Revealing mistake: After Dark Superman opens the door to the salon, the camera pans across the women inside and their reaction to seeing him enter. Watch closely at the stairs, there is a lady just randomly hovering in the air above the stairs and away from the ledge. Not touching the ground, she is actually just hovering there in an drawing error. Her waist down to her legs are visible just in the air. (00:52:55)
Revealing mistake: When Lois is going through Lex's computer, her right eye is drawn too large, and bigger than normal. (00:55:55)
Revealing mistake: After opening the door to the superman clone lab, Jimmy and Lois walk in with the light source behind them at an extreme angle. Yet their shadows are shown as if the light is right above them. It should be elongated from their front. (00:57:05)
Revealing mistake: When the military attacks Dark Superman, he cuts through their helicopters with his laser vision like a knife through butter. One of the choppers falls and crashes and burns. But the way it falls and moves in the air makes no sense, even for a cartoon. (01:04:30)
Chosen answer: When they call Doomsday a machine, they don't mean a literal machine. Just that he was built/designed. The comics were much the same. Doomsday was created by placing a baby on the most dangerous planet in the universe, and cloning that baby every time it died, forcing it to adapt. Doomsday eventually escaped this torture.
MasterOfAll