Cannot access VM via any method, although I can access other instances created on the same network

I've a Google Cloud VM instance which I restarted via SSH using the restart command. I waited for it to come back up, but it didn't seem to do so.

My GCC VM interface shows the VM is running, but it's not accessible even via webssh, or gcloud running locally, which does connect to the acccount successfully.

To test, I've created other VM instances.

Creating a VM instance using a snapshot of my disk puts me in the same situation with the new VM instance.

Creating a new VM instance from a fresh OS image and I have no connectivity issues at all. I can SSH between new VM instances, but can't SSH or even Telnet or ping to the instance I'm having trouble with.

Where can I go from here? Can I at least recover my data from the 'broken' VM instance's disk or snapshot?

Thanks.

EDIT: Here's the last few lines from the console, it seems there's a problem with the filesystem. It cannot mount ./ Can this be repaired?

 * Starting Mount filesystems on boot[74G[ OK ]

 * Starting Fix-up sensitive /proc filesystem entries[74G[ OK ]

 * Stopping Fix-up sensitive /proc filesystem entries[74G[ OK ]

 * Starting Populate /dev filesystem[74G[ OK ]

 * Starting Populate and link to /run filesystem[74G[ OK ]

 * Stopping Populate /dev filesystem[74G[ OK ]

 * Stopping Populate and link to /run filesystem[74G[ OK ]

 * Starting Initialize or finalize resolvconf[74G[ OK ]

[    9.452786] EXT4-fs (sda1): Couldn't remount RDWR because of unprocessed orphan inode list.  Please umount/remount instead
An error occurred while mounting /.

keys:Press S to skip mounting or M for manual recovery

 * Stopping Track if upstart is running in a container[74G[ OK ]

[    9.856747] random: landscape-sysin: uninitialized urandom read (32 bytes read, 30 bits of entropy available)
[    9.871893] random: landscape-sysin: uninitialized urandom read (32 bytes read, 30 bits of entropy available)
[   10.138464] random: lsb_release: uninitialized urandom read (24 bytes read, 33 bits of entropy available)
[   10.320672] random: mktemp: uninitialized urandom read (10 bytes read, 35 bits of entropy available)

EDIT: It seems the old VM's filesystem is corrupt. I've mounted the snapshot to a working VM and gotten this message: Thanks again. I've attached the disk and mounted it to another VM. I've ran fsck and gotten this message:

fsck /dev/sdb1 fsck from util-linux 2.27.1 e2fsck 1.42.13 (17-May-2015) cloudimg-rootfs: clean, 137997/1310720 files, 3602263/5242624 blocks

It was corrupt and I had to answer y to a lot of things. Hopefully it's repaired, I'll attempt to boot the vm from it.