Aquesta jugada és important.

Because jugada is a feminine singular noun, and the demonstrative has to agree with it.

• aquest = this (masculine singular)
• aquesta = this (feminine singular)
• aquests = these (masculine plural)
• aquestes = these (feminine plural)

So:

• aquest llibre = this book
• aquesta jugada = this move/play

Jugada usually means a move, play, or action in a game or sport.

Depending on context, it can refer to:

• a move in chess or another game
• a play in sports
• a strategic action
• even a figurative move in politics or everyday life

It comes from the verb jugar, meaning to play.

Because aquesta already works as the determiner.

In English, this move does not need the, and Catalan works the same way here:

• aquesta jugada = this move
• not la aquesta jugada

So aquesta already means this and directly introduces the noun.

És is the 3rd person singular of ser:

• jo sóc = I am
• tu ets = you are
• ell/ella és = he/she is

The accent is important because it distinguishes és (is) from es, which is a pronoun used in other structures.

So in this sentence:

• és important = is important

Catalan uses ser here because important is being presented as a general quality or characteristic of the move.

• Aquesta jugada és important. = This move is important.

That is a normal, standard use of ser.

Very roughly:

• ser = what something is, its identity or characteristic
• estar = a state or condition, often more temporary or situational

For important, ser is the natural choice in this sentence.

In the singular, important stays the same for both masculine and feminine.

• Aquest llibre és important.
• Aquesta jugada és important.

In the plural, it becomes importants:

• Aquests llibres són importants.
• Aquestes jugades són importants.

So the adjective does show number agreement, but not gender difference in the singular.

Yes. The basic structure is very similar:

• Aquesta jugada = subject
• és = verb
• important = adjective

So the sentence follows:

subject + verb + adjective

This is the normal, neutral word order in Catalan.

A rough pronunciation guide is:

ah-KES-tuh joo-GAH-duh ez im-por-TANT

A few helpful notes:

• j in jugada sounds like the s in measure in many accents of Catalan.
• és sounds like ez.
• Final t in important may be weak or not strongly pronounced, depending on accent.

Pronunciation varies by region, but that guide will get you close.

Yes. It can also be used figuratively for a strategic move.

For example, in a broader sense it can mean something like:

• a clever move
• a risky move
• a political move

So it is not limited only to literal gameplay, though that is one of its most common meanings.

You would make the demonstrative, noun, verb, and adjective plural:

• Aquestes jugades són importants. = These moves/plays are important.

Changes:

• aquesta → aquestes
• jugada → jugades
• és → són
• important → importants

This is a good example of agreement across the sentence.