If you are having connection problems to Game Center you may be bombarded with Game Center Achievement notifications when playing rainblocks. This was due to a slight miss on my part, but the saving grace there is that it was an easy fix. It has already been sent to Apple and given how things work it should be up in a week.
To get a bit technical, wow did I even learn a lesson about being extra thorough. A new check-mark went onto my list which basically says “make sure to test games with the device disconnected from the Internet” because that is basically the issue here. If the device is not communicating with Game Center properly, which can be for many different reasons, it will still recognize when 100% was hit and attempt to notify. If Game Center is communicating with the device it will know not to do it but without that data it fails the check. My mistake, lesson learned.