Something is lacking here, but it's decent.
I think you did a great job at making something "fun", but this really seems to lack the ability to do anything more than make noise. I thought your integration of the mouse and keyboard was impressive, but what really made me give this a low score were (what I thought) the sound effects that you chose to give the various drums/cymbals. I don't ever remember a hi-hat sounding like a tom.
At any rate, I thought you still did a fine job on this, which kept me from giving it a "Blammable" score.
You might have something here if you work on it more and present the ability to actually play this kit.