Spelling and grammar mistakes in the subtitles.
In at least one case, the subtitles are completely different from the computer message that it is transliterating.
Enemies grunt in pain from being hit even before the report of the gun can be heard.
The handle used to lower the ladder on the R.V. is called a 'steering wheel', although it isn't a wheel at all (nor is it used for steering).
One of the weapons uses 50mm bullets (or thus they are labeled). 50mm bullets, if they existed, would be far too much for an ordinary human to handle; these are probably intended to be .50 caliber rounds.
The setting takes place in the U.S.A., yet there are ruins of a Mediaeval castle - something not found in the U.S.A.