Try just pressing the Ctrl-Alt-F2 keys at the same time and see if you have a command line login prompt.If you do need to interrupt grub, you hit Esc when you first see the "Bootin... [by TrevorH]
When I click a user name on the login screen, the other ones disappear but the password prompt never shows up. It stays this way for a few seconds, then comes back to the original state with the list of users.
I am running into some strangeness trying to get 11.2 installed on a Dell Optiplex 760 Tower. The initial grub menu loads OK, and when I pick something, I get to the splash screen, and the progress bar updates once, then hangs. After a while I can Ctrl-Alt-F2 to the console, and it seems to be hung at the "Starting udev..." prompt.
Interrupt the boot at the grub prompt and append "selinux=0" to the end of the kernel parameter list. This will disable selinux and allow you to boot up. From your messages that you poste... [by TrevorH]
I followed the instructions from enzotib's answer on Making Ctrl+C copy text in gnome-terminal? to make the ctrl-c and ctrl-v keys act consistent in the terminal and then re-assign ctrl-j to be the cancel/interrupt key for ongoing processes.
The instructions works great...until I close the terminal. Next time I open the ctrl-j has to be re-assigned.