Continuity mistake: When Jack sets up the motorbike, he pivots the two bars forward and locks them to form the handlebars. A few shots later as Jack looks down at the sensor, you can see one solid handlebar, all the way across. (00:13:45 - 00:14:25)
Continuity mistake: After Sergeant Sykes shoots Jack, Jack falls to the ground and you see the bullet roll off his protective vest and lay on the floor. Moments later when they pick Jack up, the bullet has vanished off the floor. (00:58:50 - 00:59:40)
Continuity mistake: When Jack is riding his motorbike past the deserted ships, there is a huge trail made on the ground. This trail continues to be made as he rides. But as soon as he drives over a hill and stops his bike, there is no visible trail in the background, only the ships are visible. (00:14:20)