The built-in Gnome screen recorder does have limitations:

• There is no time delay options before the recordings start.
• There is no pause and play option.
• It records the entire screen. No option to record only an application window or a certain monitor.
• It only uses webm format.

A better full-fledged screen recorder is Kazam.

CTRL + ALT + SHIFT + R

This will immediately start recording the desktop.

A red dot will be displayed in the system tray area of the top panel.

The recordings are saved in webm format in the Videos folder.

CTRL + ALT + SHIFT + R

The maximum recording time, by default, is just 30 seconds.

Increase it:

gsettings set org.gnome.settings-daemon.plugins.media-keys max-screencast-length 300

This increases the maximum length of the recording to 5 minutes.

Change it to 0 to not have a limit.