I Get This Call Every Day is missing one achievement.
The Quantum Code
"We know that it is true because pieces of the code have resurfaced from people who used it before. Capcom once had part of the code; they created Onimusha with it! And then after that, they lost the code; and then they created Onimusha 2. But then they found it again, and created Onimusha 3! And now they've lost it forever; and then they created Onimusha 4. I have that piece of code: 'A T M'. But that is not all! Hideo Kojima again found another piece of the puzzle: '='. And with that amazing equals sign, he was able to create his most famous work: Zone of the Enders 2! Wait, that is not all! David Perry came into possession of a simple fragment of the code: 'R E V'. He then released Messiah and Sacrifice for the PC! Some of the most amazing programmers in the world have only had a fragment of the code. What would one become if they possessed the code itself?"
http://steamcommunity.com/stats/291090/achievements