The Chrome game that appears when there is no internet is a simple and fun endless runner game known as the 'Chrome Dino Game' or 'T-Rex Runner'.
The game begins and the dinosaur starts running across a desert landscape.
The aim of the game is to avoid obstacles, specifically, cacti and pterodactyls, for as long as possible. You make the dinosaur jump over these obstacles by pressing the spacebar (or tapping on your mobile device), and after 500 points, the dinosaur can also duck under the pterodactyls by pressing the down arrow key.
The game doesn't have an end point -- it gets faster and more difficult the longer you play, and it continues until the dinosaur eventually runs into an obstacle. The game then ends and your score is displayed, ready for you to try and beat next time you're waiting for your internet connection to come back.