Microsoft hasn't released a full title list yet, but notes that games from publishers including 2K, 505 Games, BANDAI NAMCO Entertainment, Capcom, Codemasters, Deep Silver, Focus Home Interactive, Sega, SNK, THQ, Warner Bros. and Microsoft itself will be available. A few specific games that were mentioned include Halo 5: Guardians, Payday 2, NBA 2K16 and SoulCalibur II.
The biggest difference between Xbox Game Pass and PS Now comes down to how the titles are delivered. PS Now using streaming technology to let you start up games virtually instantaneously, without having to install anything -- provided you have a strong internet connection, of course. Microsoft is actually letting users download and install the games. It'll take longer to get up and running, but you won't have to worry about the game stream cutting out on you in the middle of a battle. It's hard to say which is better without having tried Xbox Game Pass yet -- but as someone who's had some frustrating drops in gameplay using PS Now, I'm definitely intrigued at what Microsoft is doing here.
The other major difference is catalog: Sony offers a whopping 450 titles at this point, far more than the 100 Microsoft will offer at launch. But Sony's catalog is strictly made up of previous-generation PS3 titles at this point; the company hasn't given any indication that it will bring PS4 titles to the PS Now service. Microsoft, on the other hand, says Xbox One titles will be included and is offering the latest game in the Halo franchise. There's nothing on the PS Now service that's close to that fresh.
Another difference is that Microsoft says the catalog of titles available will change over time, with games being removed and added on a monthly basis. But if you fall in love with an Xbox One game, you'll be able to purchase it fully at a discount and keep it in your library.
From a pricing perspective, Microsoft is keeping it simple at $10 (£8) a month. Sony bests that, but only if you sign up at $100 for a full year. Otherwise you're paying $20 for a single month or $45 for three months. Unfortunately, interested users will need to wait a bit before trying this out. Microsoft is first rolling out Xbox Game Pass for selected Xbox Insiders; full public availability will come later this spring.