Definitely good.
This soundboard absolutely surprised me. I wasn't expecting much, but after taking a couple minutes looking at it and listening to the sounds, it's safe to say you came out with a good product.
I noticed the filesize, which can tend to be a problem with soundboards, and I thought almost 9 megs might be because of poor audio optimization. I'm happy to say that this was not the case. The sounds were incredibly clear, and your large filesize was wholly warranted.
Another thing I liked about this was the color-coding. I can't recall ever seeing that in a soundboard, and I think it's quite helpful. Even if it's not, it's still a nice touch. It means you spent a little extra time working on it.
The only problems I found were aesthetic. Some of the text was a little big for the buttons, and I found that if you move your mouse over a button where text isn't, the button won't respond. That's quite easy to fix, and I'll leave you to it.
So, all considered, this was a very good attempt with room for small improvements (more sounds, smaller size, etc.).