Here's everything that mattered at E3 2015 (pictures)

This year's E3 game developer conference is still underway, but all of the major press conferences are now behind. And that means it's time to sift through all of the trailers and promises to pick the biggest news from E3 2015.

Microsoft's Xbox One will be able to play a select number of Xbox 360 games later this year. If you bought your game from the Xbox Marketplace, you'll be able to download it to your Xbox One. If you bought your game on disc, you'll need to keep the disc in your console as a sort of authentication, and then download the game. About 100 titles will be available at launch, and developers need only grant Microsoft permission to get their older game into your hands.

Valve's Steam Machine platform is almost upon us. The aim is to bring console-simplicity to proper PCs: we've waited quite some time for these machines to make their debut, and one of the first is almost here. The Alienware Steam Machine is a black box packing Intel and Nvidia hardware, and it'll arrive as early as October 16 for folks who pre-order.

The fans asked, and clamored, and pleaded, and Square Enix seems ready to answer their wishes -- and reap the mountain of cash that fans will undoubtedly hand over to reclaim a tiny piece of nostalgia.

Don't call it a comeback: PC gaming may seem like it's been on the ropes for years, but a combination of virtual reality, living-room-friendly Steam Machines, and E-sports have seen a resurgence for the PC.

Few series inspire the same amount of fervor as Fallout, so news that Fallout 4 is on the way is...exciting, to say the least. Better still, those of us who pre-ordered the Pip-Boy edition will have a gargantuan gadget to wear on our wrists. I for one can't wait until November 10.

Valve CEO Gabe Newell hasn't had very kind things to say about Microsoft over the years, but the companies will nonetheless be joining forces on the virtual-reality front. Couple this news with word that Microsoft will be partnering with Oculus on its own VR ambitions, and it's clear that Microsoft has all of its virtual bases covered.

Minecraft and HoloLens: a match made in heaven. It turns out that the survival-oriented, castle-building and tree-punching simulator is a perfect fit for Microsoft's augmented-reality headset.

Many of us had long since written The Last Guardian off as a loss, never to see the light of day. Shame on us for doubting Sony, I guess: The Last Guardian is coming to the PlayStation 4. We still don't have a release date, but seeing some gameplay in action might just be enough to encourage us to keep hope alive until 2016.

Nintendo's bizarre E3 conference involved quite a few puppets and 3DS game, but generally played it safe. But that's OK! Nintendo fans are getting a new Star Fox game, cool Amiibo figurines to collect, and Super Mario Maker, which will let us create our own Super Mario adventures.

There was more news for Xbox One owners: a brand new dashboard is coming later this year. Microsoft is promising faster performance, support for trading messages in-game with your friends, and support for Cortana. That last bit is especially interesting: you'll be able to ask Cortana if your friends are online, or get tips on the games you're playing.