There are ten levels to OCD in Chapter Four. Once OCD is achieved on the ten levels, the achievement will unlock.
The videos below are examples of how to OCD the levels. They may not be the fastest or easiest ways to get OCD on the levels, but they will give you ideas on how to OCD the level.
The key to this game is patience, so take your time since there is no time limit.
Hello, World is an exception so try to go as fast as possible on this level (credit to W1LLYMAN).
*Note: The videos are not mine.*