I'm left wondering how long until we have mainstream video cards capable of driving games at these resolutions? Seems like we're a ways off...
For the majority of games 4K won't pose an issue whatsoever with a modern high end video card.
With a Titan card from nVidia, maxing out at 20 FPS on Unigine, it's pretty depressing. We need to see a 2 to 3x fold performance increase in graphics cards for gaming to be realistic on 4k screens.
Minimum really isn't all that interesting, though. A single low spike won't ruin a gameplay session. The average FPS was 42, the low spikes were few and far between. It's absolutely playable - that's the entire basis for which the settings were picked btw.
So, playbable, probably, but enjoyable, not so sure about that.