Every single toy missing critical pieces, and often, a lot of them. While I expect missing pieces here and there, there seems to be no quality control at all. You cannot send a kid a toy that cannot be built because essential pieces are not there, along with missing instructions, the latter of which seems pretty easy for ToyLibrary to eyeball on their end before putting it in an envelope. Further, you cannot do this three times in a row in a three month subscription. There also seems to be no customer service whatsoever, I was only able to get a response after filing a complaint with my bank for, and the response was snarky. Someone else should run with this great idea and provide higher quality and better service.