Only two to go. Colossus 14 wasn't such a big deal, since the main idea isn't unlike at least one other colossus. I thought the whole setup was a bit unforgiving: if you get caught in a corner one time, you're basically starting all over again.
I'm kind of thinking that 12 would have been a better number of colossi. I'll count the ones I thought were worthwhile when I'm done, and I'm betting I can think of 4 to eliminate.
The key will be, does the story depend on there being 16? I doubt it, but I'll find out in the next day or so.