Is there any particular reason why the max comment length is 900 characters?
I just had to leave 5 comments on this storygame due to the limit, and for each comment I would have to post the comment, press back and see how much of it has been cut off by the limit, then split the cut off part into a separate comment, rinse wash and repeat (then delete all the older comments). If I was a regular member (ie. could not delete comments) I would have had to open up a character counter in order to count the amount of characters in each comment before splitting them up and posting separately.
It seems like a lot of unnecessary effort, especially when there's no discernable reason for a 900 character limit. (If you're concerned about one comment taking up too much room on a storygame's page, you could always hide some of it and have a [see more] button, which would take up a lot less room than five separate comments.)