For people struggling to get the 14th ending, look below the spoilers tag.
The game is great, I love the characters dialogue and endings, I especially love just how much optional dialogue is there (my favourite being if the rat is still in your inventory when you put in the password)!
[SPOILERS FROM THIS POINT ONWARDS]
For people who can't get ending 14 despite seemingly doing all the other endings shown in the guide, there are 2 3b endings, you need to both be eaten trying to get the cd and be eaten trying to feed it something other than the cake.
These endings both give different signs for the Eastern wall and therefore count as two separate endings to get, this is not illustrated particularly well by the game (as they both count as ending 3b) and the guide that says that either count without specifying that completing both is needed to qualify for ending 14.