Well I spent a good 10 or so minutes just repeatedly adding links to the same page, and so far I've put on sixty without any kind of message telling me it's too many. I'll just assume that there's an infinite amount of available spaces for links on a storygame, so have fun with that.
Example
If you're looking at it from a practical point-of-view, I wouldn't go past 10 links on a single page, and I definitely wouldn't have more than just a few pages with that number of links. In reality, few people will go through every link in a storygame, or every path, and if those are for background information, then that number drops even lower. A lot of readers tend to skip optional background pages, so it would be a lot of work wasted on 90% of the community.
Good luck on your storygames, and you can always PM me for help and such.