Disclaimer
I haven't recieved any inside information on how badge decisions are made, neither have I contributed any advice to the people who make those decisions.
There is no guarantee that the requirements match what I'm measuring here; they may be more strict, less strict or entirely different.
The requirements for this leaderboard
The default requirement is to have a score recorded on the osu! leaderboards for every ranked map made for catch the beat. No loved, no coverts are required.
The only exception to this are maps that have been DMCAd. These are no longer available, so they are not required for this leaderboard.
Difficulty reducing mods such as Half Time, Easy & No Fail are allowed. This avoids restricting 100% to the very small group of players who can pass the hardest maps.
Although NF is allowed, starting a map & leaving it to play on it's own is not. You've got to actually play.
There's no way to automatically check for AFK, so any play below 50% accuracy will be flagged as suspcious & not counted.
This cutoff should remove all AFK plays while still being reachable even by new players on hard maps. In the worst case, HTNF can be used.
When you reach 100%
Do not bother random staff members, they've got other stuff to do.
The correct way to get yourself on the list to check is send an email to support[at]ppy[dot]sh, briefly stating that you have achieved 100% in catch the beat & would like to be considered for the completionist badge.
There may be some delay, there is no need to worry or send additional emails/messages. When badges are awarded, they're back-dated to when they were initially achieved
If you're at 99% & can't find the last maps
If you contact me, I'd be happy to use the same data that I use to make this leaderboard to provide a list of the maps you've missed
I'm zoggoth on Discord, osu!, github & a bunch of other sites. Discord is easiest
The data I use comes out at the start of each month. Although it is technically possible to check at any time, I would recommend maintaining 100% until the end of the month so it can easily be checked