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 a new game in its popular science fiction "Halo" series called "Halo: The Master Chief Collection," as well as other exclusive titles "Sunset Overdrive," "Forza Horizon 2," "Fable Legends" 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.
"The competing players will trot out major titles and try to establish dominance."
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 "Halo Master Chief" collection for Xbox One that will people play through five installments from the game dating back to previous generations of Xbox.
"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 Xbox One," Spencer said of the collection. "All playable this holiday season."
Microsoft played up games, downloadable content, and test-runs of online multiplay features 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 a broad array of 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.