My husband is the true gamer in the family. He has played most, if not all, of the Zelda games. Both my daughter and I watch him play but we're not as familiar with the series as he is. However, we all enjoyed the concert. There is a large video screen above the orchestra that shows videos, both game play and cut scenes, from the games. The music was beautiful and even I recognized a few of the tunes. I also thought the video screen was a nice addition. I don't always know which game is which just by the title. Having the video helped me identify each game.
The downside of the concert was the crowd. Since this is obviously aimed at gamers and not normal symphony-goers, the crowd didn't know the appropriate behavior for a symphony. While I will forgive those that wore jeans (to the SYMPHONY!), it was extremely annoying that people would cheer and scream when fan-favorite characters showed up on the screen. Yes, I understand that Epona is awesome. But I paid a lot of money to listen to the music, not you screaming your head off for a video game horse.
If the concert is coming to your neck of the woods, I would recommend checking it out. Just keep in mind that the audience will be full of people with no knowledge of social etiquette.