Continuity mistake: When Mike reaches the playground in a stolen van, his friends are there waiting with bikes. On the right we see Greg wearing sunglasses, a red cap and headphones. But in the next shot where they approach the van's rear doors, Greg is suddenly missing his sunglasses. (01:38:55)
Continuity mistake: In the first shot of Mike barreling downhill with the van, he passes by a group of three onlookers. But after Elliott figures out how to disconnect the plastic tube and lose the two men struggling within it, an overhead shot of the neighborhood shows Mike driving past the same group of people yet again (note the orange winter hat and black & white striped jacket worn by the kids). (01:37:15)
Continuity mistake: When the boys are in the garage looking for things, the light is out, door closed, and they are using torches. Cut to the outside shot - the door is open and the main light is on. This shot is shown with the van outside, then not outside.
Other mistake: When one of the bikers escaping from the cops cries "We made it!", 15 men appear from each side. Plus, there's a dozen or so police cars in front, as it is later revealed. Although this adds up for more action and suspense, it is absurd to believe neither he nor any of Elliot and Mike's friends saw none of them.