Nvidia has unveiled a gaming-focused tablet that works with a new separate controller.
The 8in (20.3cm) Android-powered Shield Tablet - which can also stream games from a PC - is the firm's second handheld device, but the first to be sold outside the US.
Many of the details of the machine were first revealed by the BBC earlier this month.
One expert said the price was "well pitched" but questioned its appeal.
"One major weakness of the Shield ecosystem is the lack of desirable games exclusives," said Piers Harding-Rolls, head of games at the IHS Global consultancy.
"Android games playable on the TV or ports of old PC games are not enough to sell this device to the dedicated gamer.
"The ability to stream games from a [Nvidia graphics card] GeForce GTX-equipped PC over home wi-fi via the device to the TV is attractive, but only to a small sub-segment of PC gamers."
Nvidia suggests the tablet offers "near-console" graphics quality when it is connected to a TV and used to stream PC titles.
But it explained the reason it could not outperform an Xbox One or PlayStation 4 was that the PC's graphics had to be compressed to be sent over wi-fi.
As a result, hardcore gamers wishing to play PC titles on their living room TVs might still prefer to wait until Valve's Steam Machines platform is launched next year.
Nvidia is charging $299/£229 for a version of the tablet with 16 gigabytes of storage, and $399/£299 for a 32GB version with an added 4G chip.
The wireless controller costs $59.99/£49.99, which is cheaper than rival premium smart device controllers from Moga, Logitech and Samsung. The firm says it uses a wi-fi connection, rather than Bluetooth, to minimise latency - the delay between a button press and a game's response.
Several controllers can be paired with the tablet at one time, allowing multiplayer gaming, however at present they do not work with other devices.
"This is the ultimate tablet for gamers," Chris Daniel, a senior product manager at Nvidia, told the BBC at a launch event in London.
"It will do everything you expect a tablet to do, and on top of that we've brought our Shield ecosystem for an amazing gaming experience."
The Shield Tablet's processor features a 192-core GPU (graphics processing unit) allowing it to run graphics-intensive Android titles natively. It can also make use of a PC's graphics card - if it is a compatible Nvidia model - to supplement the tablet's power.
This, Mr Daniel explained, offered a level of future-proofing to ensure the machine would run later Android games that would require even more power.
In addition, the tablet can stream titles run on a PC and sent to the tablet via wi-fi or 4G, assuming the data connection is fast enough.
The company suggested a two megabit per second upload and download speed was the minimum required.
Users based in California can also access the firm's Grid cloud gaming service - an experiment in which the firm offers games streamed from its own servers. This is similar to Sony's new PlayStation Now facility, which is also limited to the US at this time.
"If Nvidia can extend its cloud gaming proposition beyond a select beta test in California, then this would widen the desirability significantly," commented Mr Harding-Rolls.
The tablet does, however, include built-in support for Twitch at launch - a third-party service that allows gamers to broadcast their progress within Android games to others. Owners can include a video chat window, filmed via the tablet's five megapixel front camera and superimposed over the gameplay, allowing them to provide commentary.
Keza MacDonald, UK editor of the gaming site Kotaku, was impressed by the machine.
"It will remain niche, but Nvidia has always sold to a niche - very tech-savvy people who want the shiniest thing," she said.
"For gamers who want a tablet this will be attractive. I can imagine having this tablet next to my TV more than I can owning a Steam Machine if the streaming works as well as promised."
Despite good reviews, the original Shield Portable, which features a built-in controller, is thought to have had only very limited sales. Nvidia declined to provide any official sales figures.
That has led some analysts to speculate that the platform is, in effect, a tech demo, designed to entice other manufacturers to include Nvidia's chips and software in their devices.
But Mr Daniel said there were no plans to provide the innovations to others at this time.
"I'm not ruling it out," he said, "But the focus is on our own Shield devices for now."