Learn Russian: В таких фильмах слишком много убивают. - In films like this they kill far too much.

This is a common Russian structure used to describe actions done by unspecified people (often called an indefinite-personal sentence). By using the 3rd-person plural verb (убивают) without the pronoun они, you are saying that "people kill" or "there is killing" in general. It functions exactly like the general "they" in English phrases like "they say that..." or "they kill far too much."

The translation says "films like this", but doesn't таких just mean "such"?

Yes, такой literally means "such." While an English speaker might be tempted to literally translate "films like this" as фильмах как этот, Russian almost always expresses this idea using такой. So, в таких фильмах literally translates to "in such films," which is the most natural way to say "in films like this" or "in these kinds of films."

Is много describing a missing noun here, or is it modifying the verb?

Много is acting as an adverb here, modifying the verb убивают directly. While you are probably used to seeing много followed by a noun in the genitive case (like много людей for "a lot of people"), Russian frequently uses it directly with a verb to mean the action itself happens a lot or to a high degree.

Could I use очень (very) instead of слишком (too) in this sentence?