That was pretty freakin awesome. I always loved the choose your own adventure books. I kept playing until I had all of the endings, and I loved how the story progressed and added to itself as you 'collected' endings until you had a real good picture of the whole story. I haven't read any of the other comments, but I can only imagine you are getting mostly praise on this. A few comments to be helpful:
1. In your in-game commentary you are right, the artwork doesn't always suit what is going on in the story. That could be improved upon, but it really didn't detract. It just would make it even better.
2. Of course even though this was all discombobulated, it would have been awesome if the story was even longer.
3. Not really a suggestion, but one thing I did like is that despite all of the things that happen in the story you do keep everything consistent. Many choose your own adventure tales the different endings are completely unrelated, sometimes existing in obviously different universes. Granted that can be fun too.
All in all great work. 5/5 9/10 Keep it up.