A good example would be Grass Cut or Helix Jump.

The main differences: - anyone (that includes kids and non-gamers) should be able to easily pick up and play the game - the simplest input possible, usually just tap anywhere on the screen - simple (primitive) graphics with high contrast and readability (again, so it doesn't confuse non-gamers)

So it's like a casual game but even more simplistic and stripped out of any depth.