What is it generally about?
Post college graduation angst. Destiny. Talking smushed faced wax lions.

Why was it cancelled?

It was on Fox and wasn't hosted by Ryan Seacrust.

Did it deserve cancellation?

Of course not.

Is it worth watching only one season?
Yep, totally. It's a complete story. They did well closing it out.

Is it one of those underrated classics or nothing special?
Underrated classic. Not the best "cancelled before its time" show. But definitely up there.

Bryan Fuller is a television genius. Not up to Joss Whedon's standards, but pretty close. Give it a chance.