Re: not brilliant
You're right that "not brilliant" is being used as an adjective. It's definitely not standard English but I can imagine hearing it. If I were trying not to be too rude about something, I might describe it as "not brilliant" to show that perhaps it wasn't as good as I had expected, but it was still good. Note though that that is just my take on it, it doesn't have a standard definition.
Originally Posted by navi tasan
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.