Learn Hardcore Portuguese (Portugal): Hoje o ritmo do filme é lento, mas eu gosto. - Today the pace of the film is slow, but I like it.

In this sentence, é lento presents the film’s pace as a characteristic of the film (how the film is, as a work). The idea is more “the film’s pace is slow (that’s the kind of film it is).”

If you said Hoje o ritmo do filme está lento, you’d sound as if:

the slowness is something temporary or unusual, or
you’re talking about a particular moment/phase (e.g. “right now the pace is slow”).

Because the pace of a specific film doesn’t change from day to day, é lento is the more natural choice here.

In English I’d say “but I like it.” Why is there no “it” in mas eu gosto?

In Portuguese, gostar usually needs de plus what you like:

Eu gosto do filme. = I like the film.

In mas eu gosto, the object (do filme / “it”) is simply left out because it’s obvious from context. Native speakers do this a lot:

O filme é estranho, mas eu gosto.
“The film is strange, but I like (it).”

If you want to include an object, you can say:

Mas eu gosto do filme. – more explicit
Mas eu gosto dele. – “But I like it / him” (referring to o filme).

What is do in o ritmo do filme? Why not just de o filme?

Do is a contraction of:

de
- o → do

So, literally:

o ritmo do filme = “the rhythm of the film / the film’s rhythm”

In European Portuguese, de + o / a / os / as almost always contract:

de + o → do
de + a → da
de + os → dos
de + as → das

Writing de o filme is grammatically wrong in standard Portuguese; you should use the contraction do filme.

Why is hoje placed at the beginning without a comma: Hoje o ritmo do filme…?

Time expressions like hoje, amanhã, ontem often go at the beginning of the sentence, and a comma is optional in everyday writing:

Hoje o ritmo do filme é lento…
Hoje, o ritmo do filme é lento…

Both are acceptable. With a comma, you pause slightly after hoje. Without it, the sentence flows more continuously. For a learner, you can treat both as correct; style and rhythm of speech decide whether people write the comma.

Could I say O ritmo do filme hoje é lento or O ritmo do filme é lento hoje? Is the word order flexible?

Yes, you can move hoje around, with small changes in emphasis:

Hoje o ritmo do filme é lento…
Neutral, very common; focus first on today as the time frame.
O ritmo do filme hoje é lento…
Slight extra focus on o ritmo do filme first, then you add hoje.
O ritmo do filme é lento hoje…
Can sound a bit more contrastive: “The film’s pace is slow today (as opposed to other times).”

All three are grammatically correct. The original version (starting with Hoje) is the most typical way to introduce a time reference.

Why is it o ritmo do filme and not something like um ritmo or just ritmo do filme?

Portuguese uses definite articles (o, a, os, as) more than English:

o ritmo do filme literally: “the rhythm of the film / the film’s rhythm”

Here, we’re talking about a specific film that both speaker and listener know, so o (definite article) is natural.

Compare:

O filme é lento. – “The film is slow.” (a particular film)
Um filme lento. – “A slow film.” (any slow film, not specified)

Saying just ritmo do filme without o at the beginning would sound incomplete; you normally need the article: o ritmo do filme.

Can I drop eu and say …mas gosto instead of …mas eu gosto?

Yes. Portuguese is a “null subject” language: you can usually omit the subject pronoun because the verb ending already shows who the subject is.

Mas eu gosto. – “But I like it.” (with emphasis on I)
Mas gosto. – “But I like it.” (more neutral, subject understood from the verb form)

Both are correct. Using eu adds a bit of emphasis or contrast (“others might not, but I do”).

What’s the difference between lento and devagar? Could I say o ritmo do filme é devagar?

Lento is an adjective; devagar is an adverb.

lento = slow (describing a thing: a film, rhythm, person, etc.)
- O filme é lento. – “The film is slow.”
- O ritmo é lento. – “The pace is slow.”
devagar = slowly (describing how something happens / the manner)
- O carro anda devagar. – “The car goes slowly.”
- Ele fala devagar. – “He speaks slowly.”

So:

Hoje o ritmo do filme é lento ✔️
Hoje o ritmo do filme é devagar ❌ (sounds wrong/nonnative)

You could use devagar with a verb instead, for example:
Hoje o filme anda muito devagar, mas eu gosto. – “Today the film is moving very slowly, but I like it.”

Why use ritmo to talk about a film? Is it the same as “pace”?

Yes, o ritmo here is very close to English “pace” in film/TV/book discussions.

Common uses of ritmo in this sense:

O ritmo do filme é lento / rápido. – “The film’s pace is slow / fast.”
O livro tem um bom ritmo. – “The book has a good pace.”
A série começa com um ritmo muito lento. – “The series starts with a very slow pace.”

You could also hear andamento in some contexts, but ritmo is very standard for talking about how fast or slow a story unfolds.

Should there be a comma before mas in …é lento, mas eu gosto?

Yes, a comma before mas (meaning “but”) is normal and recommended:

…é lento, mas eu gosto.

Just like in English “..., but I like it.”, the comma marks the change from the first idea to the contrasting idea.

In informal texts, some people might skip the comma, but the standard, clear way is with the comma.

How is this sentence pronounced in European Portuguese?

Approximate European Portuguese pronunciation (Lisbon-like):

Hoje – [ˈoʒ(ɨ)] – like “OH-zh(uh)” (the final vowel is very weak)
o – [u] – like “oo” in “food”, but short
ritmo – [ˈʁitmu] – initial r is a guttural sound in the throat, like French r
do – [du]
filme – [ˈfiɫm(ɨ)] – l is “dark” (tongue back), final vowel very weak
é – [ɛ] – open “eh”
lento – [ˈlẽtu] – en is nasal (like saying “len” with air in the nose)
mas – [maʃ] – the final s sounds like English “sh” in most of Portugal
eu – [ew] – similar to “eh-oo” blended into one
gosto – [ˈɡɔʃtu] – os sounds like “awsh”

Spoken naturally, syllables link a bit:

Hoje o ritmo do filme é lento, mas eu gosto.
[ˈoʒu ˈʁitmu du ˈfiɫmɛ ˈlẽtu maʃ ew ˈɡɔʃtu]

Does hoje always mean literal “today”, or can it mean “nowadays” too?

Hoje usually means literal “today”:

Hoje o ritmo do filme é lento. – “Today the film’s pace is slow.”

However, in some contexts, hoje can extend to “these days / nowadays,” especially in general statements:

Hoje os filmes de ação têm muito efeito especial.
“Nowadays action films have a lot of special effects.”

In your sentence, it’s most naturally read as literal “today,” meaning “in today’s screening / the film I’m watching today.”