At around 1:13:12, when the magma creature grabs the back of the Deep Digger, the animation of the reactor detaching is shown about 16 seconds before it's supposed to be detached.
At around 1:14:13, when the Deep Digger emerges from the volcano, it's reactor is back when it is supposed to be detached.
In some scenes some of the female soldiers' bra straps (seen sticking out from their tank tops) change from black to taupe/tan.
At around 46:50, wooden stairs can be seen on the right.
At around 1:15:16, a water tank can be seen at the top right of a hill.
At around 13:18, houses can be seen in the distance on the left and right.
At around 55:09, the puppeteer for the spider legs can be seen on the left.
Throughout the film, the camera can be seen as a reflection on Gretchen's glasses.