The new Galaxy S4 could outperform the iPhone, experts have said after Samsung challenged Apple on its rival's home turf.
The device, which allows users to control the screen using their eyes, is expected to pose the greatest threat yet to Apple's flagship phone.
Industry experts predict it could even tip the balance in favour of the South Korean electronics giant as the two companies wrestle for top spot in the smartphone market.
Critics have already lavished praise on the new device - unveiled yesterday at New York's Radio City music hall - with some predicting the S4 could take a large bite out of Apple's market share.
The launch event itself was shrouded in secrecy until the last possible moment, meaning Samsung achieved a fever-pitch level of excitement more commonly associated with its California-based competitor.
Ernest Doku, telecoms expert at uSwitch, said the S4 "more than" lived up to its hype and will have "worried" Apple.
"They have taken the fight to Apple's back yard," he said.
"This could tip the balance in Samsung's favour until we see what Apple's defence might be.
"It was October last year when the iPhone 5 came out so presumably it will be a little while before we see their rebuttal.
"They clearly do see Samsung as a threat and I think they are going to have to fire on all cylinders to deliver something genuinely novel to turn the focus back on them."
Predicting the S4 could become the "biggest handset of the year", he added: "Pricing will be the final piece of the puzzle, and if Samsung can get it right, then the Galaxy S4 could take a huge bite out of the smartphone market at the end of April."
Paul Thompson, managing director of mobile advertising company BlisMedia, suggested the S4 would set the benchmark on how a mobile device could be integrated into daily life.
"There is certainly enough to set the Galaxy S4 apart from the iPhone 5 by some distance," he said.
The S4 can stop and start videos depending on whether someone is looking at the screen, flip between songs and photos at the wave of a hand, and record sound to run alongside snapped still pictures.
But observers have expressed doubts about some of the phone's features.
These include technology which enables the user to change music tracks or accept a call with a simple wave of a hand, and a "smart pause" that stops video when a viewer looks away from the screen.
Stuart Miles, founder of technology and gadget site Pocket-lint, said the S4 offered "an incredibly powerful handset" that would sell well but insisted Samsung's device took the smartphone "one step forward rather than two or three".
"I think it will be an incredibly popular phone," he added. "If someone is getting fed up with the iPhone, and there are a lot of people like that, then it's a compelling offer."
But he said many of its new functions - such as an inbuilt translator - already exist elsewhere while others could become a headache for users.
"I think a lot of people will get baffled and either not use half of these things or be frightened by them because it may not be intuitive," he said.
The plethora of new features "are good steps in this direction, but they can be seen as gimmicks rather than game changers," said Jan Dawson, chief telecom analyst at IT research outfit Ovum.
"At this point, Samsung appears to be trying to kill the competition with sheer volume of new features."
"For now, Samsung can likely rely on its vastly superior marketing budget and the relatively weak efforts of its competitors in software to keep it ahead."
Samsung is said to be expecting sales of its new handsets to be as high as 10 million per month, largely driven by its new features.
Marketed as "slimmer and stronger", the S4 weighs 130g and is 7.9mm thick, while its AMOLED technology means the screen has a resolution of 441 pixels per inch.
Among its most heavily emphasised features was the remote technology which allows users to control functions without touching the 5in (12.7cm) screen - a bigger display that the S3's 4.8 inches.
But because the new display will cover more of the phone's surface area, the device itself will be the same length and slightly narrower, thinner and lighter than the previous generation.
The S4 will use either Samsung's own applications processor or Qualcomm's Snapdragon central processing chip, depending on the country
The "smart scroll" function enables the S4 to detect the movements of the eyes and wrist, meaning users can scroll through emails without touching the screen, by simply tilting it forwards or backwards.
A dual camera function lets users take photos or video using a 13 megapixel rear camera and a 2 megapixel front camera at the same time. Images can then be blended together.
Samsung is also promising an instant translation between 10 different languages for certain applications, as well as a separate translation application on the device.
The phone can translate voice or text, measure temperature and humidity and automatically create "story albums" of photos and videos, which can be synchronised with other devices.
Users will be able to activate commands via voice control when driving and even monitor their health.
The S4 will be available through 327 mobile operators in 155 countries, including Orange, EE and Vodafone.