I realize there is already a thread about this but apparently no one in that thread actually understood what they were talking about.

Yesterday after signing up for Stick Empires I confirmed my account and went on to play for an hour or two, but now when I go back to the website the only page I can view is the registration page, I've even tried making a second account and that didn't work. Has anyone else had a similar problem today? I was really enjoying the game and I am kinda annoyed that I can't get back onto it.

The registration page is stickempires.com
Go into your email, re-read the email for it, and it should have the link to the game, there

When you go to stickempires.com, there should be a "Already registered? PLAY NOW!" button.
Maybe it's just for me though...
Edit:
Try the link(s) from your email again.