Yeah, sounds like the Surface is about what you're looking for -- the Surface RT only runs limited, App Store-provided programs, while the Surface Pro sounds well out of your price range.
I'm surprised by the negativity toward Asus -- the Nexus 7 is a legitimately excellent tablet, and their full-on Win8 laptops are pretty solid in my experience (my wife's had two (first one was stolen)). I've always thought of them as a pretty solid brand.
Course, I've never had a high opinion of Acer and yet here I am buying their Chromebook. Reversals abound!
I'll let you know how the Chromebook goes, BTW -- "Ubuntu on a Chromebook" actually sounds like a pretty good match for what you're talking about. It's not Windows, but it'll run the Linux version of Steam just fine; indie games abound and yes Minecraft runs on Linux too. I've opted for the non-touch version, but the touch version is only $50 more if that's something you're jonesing for.
I'm not saying go right out and buy one, even if that does sound like something you'd consider; I'll let you know how installation goes. (I've found that Chrubuntu installation scripts are finicky as hell on the Samsung Chromebook and if you don't have exactly the right one it can easily break partway through an install. Course, I'm not sure if the BIOS is as locked down on the C720; you might not even need Chrubuntu. I'd just as soon take ChromeOS off entirely and just run Xubuntu.)