Yeah, it's low res and low frame-rate video.
Volume buttons are universal to almost every Android device, two of them usually as "one button" so when you press in the middle you can get third button press. I prefer when they are on the right side, but even if on the left you could use your thumb. These buttons are usually nice and gentle, so that's also why you can't see much of "pressing" motion in the video.
There is that volume button on the right hand side on that phone in the video, I'm using my index finger to jump in Donkey Kong.
In horizontal mode, say for Track & Field, I chose to put those volume buttons on top, but Metal Gear I play on another video I play with those buttons at the bottom. You can map any buttons to whatever input you like, and I'll also make touchscreen in next version act as one of the buttons.
Small phones, 240x320 as in the video, are best for sensor play, larger phones are harder to hold steady when pressing buttons.
It's really fun to play, just as it looks (I hope).