Nope, does not work as documented.
Followed their docs to the letter. Tried VNC (two different versions) and RDP. Looks like a firewall issue and I do not have the time to troubleshoot their offering; will build my own in the time it takes to fix this broken template. Word to you guys; more complete docs are needed. I have been using the VNC server and clients for years, so I know the issue was not on my end.
If you use the default security group that comes with AMI, the firewall should be configured properly for all access methods (http, https, VNC and RDP). However if you like to use your own security group, please open the following TCP ports for incoming connections: 22, 80, 443, 3389, 5900. Thank you for your suggestion on the documentation. We are adding the firewall port info in the usage instructions.