If you need an example of how the Xbox One's initial lack of self-publishing hurt it, look no further than Transistor. In general, look no further than Transistor. Why would you want to look at anything else? It's so damn pretty. Jen Zee is the best.
Anyway, the wildly successful (and super good) Bastion was a huge hit on XBLA as well as PC/Mac, the eventual browser version, and the iOS version (it's sold over 2.5 million copies overall).Transistor is coming to PC and PS4. Prior to E3, Sony asked Supergiant if they wanted to debut the game at their conference, which Supergiant initially said no to. "But as we learned more about the PS4," creative director Greg Kasavin explained. "we were very impressed by what we saw, and Sony had a very open stance toward smaller teams like ours."
Kasavin also said, "we're not tied down to any one platform," noting the PC release, but right now they're only building the PS4 and PC versions, which should be out this year. It's the same reason the small-ish team at Supergiant didn't bring Bastion to Android after the successful iOS release. They didn't want to farm it out and they wanted to work on a new project.
Check out the whole interview piece with Kasavin for some more backstory on the studio and talk about the combat system.