The on-screen keypad mirrors the original key layout, and the timing of the snake is the original timing: measured, not approximated. Haptic feedback clicks like real keys. External keyboards and gamepads work too, which turns an iPad into a very fine snake machine.
After the first launch the game runs entirely on your device: aeroplane mode, subway tunnels, nowhere-cabins all fine. Your permanent high score, statistics and 27 challenges stay on the phone, and no account is needed.