Continuity mistake: The close-up view of the five stones on the rock was different from the distant view. The shape of the larger rock they were on had a dip in it (left-center) and had a bigger arc to the right. The five stones were arranged (spaced) differently even after accounting for the different angles and distances at which Mikey saw them. For example, the two stones on the left side were further apart and the two stones on the right side lined up more vertically. (00:06:13)
Continuity mistake: After Mikey fell through the (sink) hole, he had dirt/dust on his glasses (right lens). Mikey then crawled through the cave on his hands and knees and his glasses were clean when he stood up. (00:05:32 - 00:06:11)
Continuity mistake: Mikey dropped the wristwatch Andrew gave him and it landed face down with the bands upward. When Mikey jumped off the rock to retrieve it, the watch's face was on its side (visible to the screen) and the bands were parallel to the ground. (00:05:04)