Instant Replay is a fun feature that is found under the 'View' drop down item. A simple dialog box is presented with a couple of options, Duration and View type. A value of 0 for Duration will replay the entire flight. The default value is 90 seconds (similar to MSFS). If you want something different, just type the number of seconds desired in the text box. The View option is a drop-down with three options corresponding to Cockpit, Chase and Tower views. No matter what this is initially set to, the view type can be changed as normal with v/V and ctrl-v to cycle forwards or backwards through all the available views or return to default Cockpit view.
To return to normal flight, press 'p' a couple of times. This returns you to the point you selected Instant Replay. You cannot back up 30 seconds or so and try that landing again.