@catgrep While in the VM (captured) hitting ESC while booting will display LL boot process - Hitting ESC again display the grayed/ circle loading screen --- this is after boot options/grub (could be very quick to this point)
If you didnt see the grub screen = Close the window, dont save state - power off... Then boot again Grub should display...
Ubuntu is likely the top option - Choose Advanced Options for Ubuntu --- Could say Linux Lite vs Ubuntu and hit ENTER
You will have various Kernels and Recovery to choose from ...
Try the upper most Recovery see how it fairs - else try the previous (2nd most current) kernel version (non recovery) this should be the state it last booted, prior to updates.
Post back success or not...
Check disk etc etc.. you can try rerunning updates and see where it crash....
This is a RECOVERY option
Snapshot is within VirtualBox - if you created one..
or are you referring to TimeShift? - within LL --- you would need access to terminal/tty