Once a round is started, the players do not stop moving forward (unless the game is paused). All you have to do is avoid crashing by changing your players direction. Additionally you can try to hinder your opponent. For this it is possible to increase the velocity by pressing your accelerator key.
A round starts when all human players press a direction key. The initial moving direction is then in this direction.
If you want to interrupt playing, select from the menu or hit the keyboard shortcut (see section Default Shortcuts). Additionally the game is paused when the game loses the keyboard focus, e.g. when switching to an other window.
To continue the game, select the menu item again, or the keyboard shortcut. The game will also continue if the human players press one of their direction keys. But be careful, your player switches to this direction immediately.
A game consists of several rounds, and ends if a player has at least nine points, and additionally two more points than the opponent. The current score is always displayed in the status bar.
You can change the difficulty level of the game using the game menu item or the select box on the status bar. The difficulty influences the speed of the game and the computer player.