My brother's wedding was 14 people, back in 2011. It was lovely. They had a beautiful setting, which helped, but my brother and his wife aren't at all wedding focussed so they left it to my brother's MIL to organise. She made everything very formal and elegant, so we were all dressed up, there were lovely flowers, the wedding breakfast was in a gorgeous room with open fires and candles (it was January in a medieval German village; there was snow on the ground). There were lots of speeches - nearly all the adults present stood up to speak! - and she'd collected messages from the people who couldn't be there. There were also some lovely traditional gifts sent in from people who weren't there. We all had to get involved - making a speech, or opening a message to read it, or whatever, and that worked really well.
What didn't work? Dancing! They wanted to do a formal bride/groom dance and it was just awkward, and then they tried to have more dancing. It's just too few people!
I also think piped music for the ceremony doesn't work. It sounds silly to say that, but when there's only a handful of you in the room, you hear every click and tap of getting the CD ready (or these days, hitting play on an ipod or whatever), and it feels very strange. No music at all would have been better!
But I think having everything done absolutely beautifully, with thoughtful detail, made it special. It felt really intimate and lovely. I'm sure your wedding will be beautiful too - good luck! And congratulations.