How do I loop an Impress Presentation until I press escape?

First, the slides need automatic transitions defined. To set that up:

  1. To set that up, select Slide Transition in the task pane (right).
  2. Under Advance slide choose Automatically after and set a time.
  3. Click the Apply to All Slides button (or set a different time for different slides).
  4. Set the looping from the main menu, choose Slide Show > Slide Show Settings.
  5.  In the dialog, choose Auto and set the spinner for the period of time to elapse between the end of one cycle and the beginning of the next. If you want continuous viewing, set it to zero.