Microsoft aimed squarely at hard-core video game players on Monday, opening fire with Halo and a barrage of other titles for play on its new-generation Xbox One consoles.
Unveilings of blockbuster and enticing exclusive content came during an Xbox media briefing on the eve of the opening of the annual E3 video game extravaganza in Los Angeles.
Microsoft's opening salvo in the battle to dominate E3 and invigorate Xbox One sales was to be met with return fire from Sony, which had its own grand event touting PlayStation 4 titles planned for later in the day.
The US tech giant announced the release for later this year of an addition to its popular science fiction Halo series called Halo: The Master Chief Collection, as well as other exclusive titles Sunset Overdrive, Forza Horizon 2, and Dance Central Spotlight.
"We are committed to delivering amazing experiences that will help define this generation of games and delight the millions of passionate Xbox fans around the world," said Phil Spencer, head of the Xbox division.
"Our goal is to make Xbox One the best place to play games this generation."
Microsoft brought the focus back to games in a shift from stressing how Xbox is evolving into a multipurpose entertainment center for films, television, music, and more.
At the end of the day, what sells video game systems are blockbuster games, said Phoenix Online Studios manager and strategy analyst Scott Steinberg.
Sony goes into the video game industry's biggest annual trade show with an edge, its PS4 having trumped Xbox One in sales since the competing consoles hit the market in November.
'Master Chief' collection
Microsoft played to its strength with a Halo Master Chief collection for Xbox One that will let people play installments from the game dating back to previous generations of Xbox.
Typically older games aren't compatible with new-generation consoles, but the collection brings the array of Halo titles to Xbox One as a draw for new players as well as fans interested in replaying the past.
"It's massive," said Bonnie Ross, general manager of 343 Industries unit of Microsoft Studios behind Halo.
It is also setting the groundwork for the future.
The Master Chief collection will contain a live action series based on the franchise and produced in collaboration with filmmaker Ridley Scott.
The Halo Nightfall series is coming to the Xbox Live service for online game play and digital content, according to Microsoft.
Now players can experience the whole Halo story, only on Xbox One, Spencer said of the collection. All playable this holiday season.
The collection also comes with access to a private test of a Halo 5: Guardians online multi-player game set to launch next year.
Microsoft played up content that will only be found on Xbox One. Sony is expected to do likewise with game play, titles or features people will only find on PS4.
While many blockbuster titles from third-party studios or publishers have versions tailored for both platforms, Microsoft and Sony are keen to convince gamers that their console is the better place to have fun or find entertainment.
Sony and Microsoft have also been courting independent game makers to add quirky or innovative new titles uniquely to their respective consoles.
Kevin Spacey gets game
Spencer touted that downloadable content for a keenly-anticipated Call of Duty: Advanced Warfare game, complete with a character played by a virtual version of actor Kevin Spacey, will arrive first on Xbox One.
Advanced Warfare is slated for a November release.
A sassy Sunset Overdrive game exclusive to Xbox One is set in a world where a contaminated energy drink turned most inhabitants into mutants, and some of those unaffected are taking advantage of the chaos.
Players take on the role of a wise-cracking, denim-clad hero who jumps, wall-runs, surfs power lines and more while blasting away with unusual weapons.
The title by Insomniac Games is due out on Xbox One in October.
Microsoft also touted Project Spark, which will let players create their own game worlds for one another.
Sony has already fired back, teasing PS4 titles The Last Tinker: City of Colors and Fluster Cluck, described as a cosmic adventure.
Watch: New Xbox One Titles Hyped at E3