The crypt seems a bit buggy, not sure if the stuff going on with it is intended or not.

First time I went there, around 10 past the hour, it said the gates were locked. I waited until 17 past and it said the same thing. I tried again 32 past and finally got a bone. Then I tried again 46 and it said I got a bone, but I didn't get anything. So I tried clicking again just to see what was going to happen, and it kept saying I got a bone, even though I was getting nothing. o_O

Then I deicded to wait a few minutes and just went to try again. 49 past it said I got a bone, but I seem to have gotten a skull instead, and whenever I click the crypt now I keep getting the message that I got a bone, even though it's not giving me anything.

I dunno if the message for the bones/skulls/ribs (which look like brains to me :XD) are meant to be different though. :P Or if every 15 min means set times or 15 min from the last time you received something.