Guess the Intro doesn't try to load all playlists - it just takes what it can in a few seconds and goes with it.
Loading the entire playlist tree (especially if you're also trying to load all the tracks) can take quite a while in CocoaLibSpotify, especially on first run since nothing is cached.
Typically, for UI, you'll only want to load the playlists for display (and not their tracks). When the user chooses the playlist, you then start loading the tracks for display.
Loading all the playlists and all their tracks at once like Guess the Intro does puts significant strain on the system and all that metadata will take a long time to load. If you really, really have to load everything at once, 1) prepare for crash reports from your users who have lots/large playlists and 2) give a much longer timeout.