Interesting. It would seem that you are not getting the much touted albeit a bit confusing automatic failover "Advanced Boot Menu Options"
And to take this even further, we’ve removed even this one remaining keystroke by automatically loading the boot options menu when there is no way to successfully complete Windows startup.
In Windows 8, this automatic failover behavior will take you directly to the boot options menu whenever there is a problem that would otherwise keep your PC from loading Windows. This even includes cases where it appears (to Windows) that boot has succeeded, but in actuality the PC is unusable.
SOURCE:
Designing for PCs that boot faster than ever before - Building Windows 8 - Site Home - MSDN Blogs Try interrupting the auto restart yourself by either hitting the reset button if available or holding down the power button until the PC shuts down and then reboot and see if you get the advanced menu options.
Otherwise you will need to either boot to the Recovery Environment using a Windows 8 Repair Disk or the Installation Media.
Select your keyboard layout
And then try some of the options available to you from within the Recovery Environment.
Windows Startup Settings (if available) should allow you to boot into safemode (fingers crossed)
The Troubleshooting Option supports some other advanced options like
Advanced Options:
System Restore .... this may help, assuming that you have managed to start the system successfully in the past and something you have done in the interim has cause your difficulties.
System Image Recovery..... provided you have had the foresight to create a previous Image
Automatic Repair..... similar to Startup Repair, maybe useful if there is corruption with respect to boot files.
Command Prompt.... some more advanced options with respect to addressing more advanced and consequently more complicated repairs using tools like bootrec.exe, bcdedit, chkdsk, etc.,
You may also wish to consider other recovery options if available like
Refresh
OR
Reset
Here's a pretty good link that goes through most of your options in some better detail
Repair your computer in Windows 8 | www.winhelp.us