At the very beginning of the movie when it shows the meteor hitting the earth it is clearly daytime, yet when the campers leave their tent to investigate, it's dark.
After the camper who went back for the camera is attacked in the tent, his bloody arm comes through the flaps and his hand grabs a sapling. Right after the hand closes, the shirt changes from light faded denim to a very dark color, and the hand appears to be somewhat larger.
When Bunny is making her green sauce, the spawn that crawls into her food processor clearly is not there when the food processor is glimpsed in a long shot.
After she narrowly escapes being eaten by the mother spawn and is pulled to safety inside Charles' bedroom, Kathy has her hands up around her own head in one shot, then she's pulling up one side of her shirt in the next shot.
The decapitated body is seen from the roof at 1:03:53. When it is seen again from the attic at 1:05:14, the image is reversed.