Goofs

When Erin kills the last of the masked men in the basement, she is drenched with his blood (which is visible in the camera flashes as she stands and looks at him). However, when she goes back upstairs in the next scene, she has much less blood on her and no more blood in her bangs.

When the guy is killed with the blender at the end you can clearly see him still breathing whilst he is lying on the floor for the entire shot.

When Crispian is leaving and saying goodbye to Erin, in one shot their heads are nearly touching as they lean together. The shot then changes and their heads are far apart and Crispian is standing up straight, not leaning inward.

The machete in Aubrey's head has disappeared when Zee attempts to seduce Felix on the bed with Aubrey's dead body.

When Drake, who has just been shot in the back, runs from the dining room, you can see the protective shield under his shirt where the arrow goes into him.

The production accountant's credit includes the misspelling "accountain".

Drake is shot in the back with a hunting bolt which averages twenty inches in length with a razor broad head. The bolt has apparently passed through his lungs and perhaps his esophagus. Regardless, a man is no different from a deer here. He would be dead from blood loss in a very few minutes. On top of that, he moves around which would slice his insides up even more. If they had used target points, it could have worked. Broad heads kill, and they kill fast.

When Erin escapes the house and immediately climbs in the window to the kitchen - after the sheep head killer gets stabbed in the head and backs up you can see hoses(?) on his back which must be for the blood spurt.

Around1:24:07 during the kitchen scene, as Erin sits on the floor in front of the oven you can see a reflection of a camera.

After the first arrows are being shot through the windows, nobody even bothers to shut down the lights, which would be the logic thing to do.

It's odd that it doesn't occur to anyone that Felix might be involved, after he basically choreographs his sister's death-he was uncannily specific in instructing her to rush straight out the door as it was opened, etc.

Erin is supposed to be adept at self defence due to her survivalist upbringing, yet multiple times, after getting the best of one of the masked killers, she does not pick up and use the weapons they had (an axe and a machete) to arm herself. The only weapons she uses are knives and a meat tenderiser, both of which can only be used at close quarters. Whilst Erin proves herself adept at using such weapons, a wiser choice would be to carry the longer weapons and the shorter ones.