BARCELONA, Spain — While thousands of companies are about to descend on this seaside city for Mobile World Congress, arguably none has more at stake than LG Electronics.

The South Korean electronics maker plans to unveil its new premium phone, the Android-based G5, at the world’s largest mobile trade show next week. The goal for LG is straightforward yet daunting: halt its slide in market share and relevance even as the overall smartphone market is cooling.

Smartphone performance falters

LG makes a wide range of electronics and appliances in addition to smartphones. But in 2015, weakness in its smartphone and TV business caused annual revenue to fall to $48.8 billion from $50.98 billion in 2014.

The company actually saw a slight increase in the number of smartphones it sold in 2015  — 59.7 million, up from 59.1 million in 2014. But pricing pressures meant revenues from smartphones were down a bit.

The performance in 2015 continued a downward trend for LG. In 2013, LG was number four in global market share, shipping 47.7 million phones and just a hair behind Huawei, which took the third slot.

Since then, Huawei more than doubled its annual smartphones sales to remain third behind Samsung and Apple in 2015. LG’s modest increase over two years has dropped it to sixth place, far behind Lenovo (four) and Xiaomi (five).

And LG is only expecting things to get tougher this coming year.

“The smartphone marketplace is expected to be increasingly competitive in 2016 due to anticipated premium models from competitors and further price competition within the mass tier space,” the company said in its earnings statement. “The introduction of two new flagship models and a more cost-competitive value chain is expected to improve profitability in 2016.”

Enter the G5

As Evan Blass wrote at VentureBeat, the all-metal G5 will feature significant updates to its cameras, bio sensor capabilities and display, as well as a “Magic Slot” to make the phone LG’s “most premium handset to date.” In a recent update, Blass noted that the “Magic Slot” will allow users to swap in and out various modules that expand the phone’s functionality. Various partners who are making such modules are expected to be highlighted at the event, as well.

In starting the marketing drumbeat for the G5, LG put out a tongue-in-cheek press release last week trumpeting a new “Quick Cover” for a “smartphone that does not officially exist.” The new cover is meant to highlight the G5’s rumored always-on feature.

The company also pre-announced a revamped version of its phone that comes with a stylus. The new LG Stylus 2 is the successor to the G4 Stylus and comes with a new stylus that the company says has a “nano-coated tip for more accuracy compared to the previous rubber-tipped pen.”

Finally, the company also announced that on Sunday it will unveil a new line of more moderately priced “X series” phones. These mid-range phones each contain a singular high-end feature (i.e., X cam and X screen phones) that are geared primarily to markets in Asia, Latin America, and Europe.

Go big or go home

To ensure the new lineup of phones gets maximum exposure and impact at a show that attracts 80,000 people, LG has a weekend full of media-related events to talk up the company’s prospects.

It’s never easy to stand out at a show where thousands of smaller announcements are made, and where Samsung has its annual circus-like Unpacked event on Sunday to announce its new flagship phones.

LG will counter this media storm starting on Saturday, by inviting press to an exclusive breakfast in Barcelona with Dr. Ramchan Woo, LG’s vice president of product strategy and its leading smartphone designer.

The company has dubbed Sunday “LG G5 Day” and is holding its own splashy press conference in the early afternoon, a few hours before Samsung’s.

Patrick Moorhead, president and principal analyst at Moor Insights & Strategy, is optimistic that LG can deliver some solid technological advances that will help it stand apart from rivals. But Moorhead also said that marketing has been a traditional weak spot for LG and noted that it needs to improve its game this time around.

“LG makes some very good products, particularly with their G4 line,” Moorhead said. “LG’s biggest challenge is its marketing, where they fail to really suck in the consumer and explain why all these new features matter.”

No doubt, if LG wants to regain its smartphone momentum, it will need to start by sticking the landing at MWC this weekend.