Big fan of this teaching game. I rate this game as my best ever experience (Braid, Seven Kingdoms are two and three rank respectively now).
Clicking on ‘Play Circle Walking’ this link: http://us3.campaign-archive2.com/?u=c86c5e56e46659873417a8f1c&id=03a7bbfd67, I can access the first level of Kelvintaph Glacier sans unlocking the world (yet). Is this intentional? To tease players, etc? I haven’t tried playing it and checking if I can submit solution and earn the diamonds to my account (or if finishing it can repeatedly pump diamonds into my account ).
Hope this is not an adventurer level that I accidentally came across.
It is also accessible by guest user (without CodeCombat account, checked by logging in by Chrome Incognito mode). But alas, not the available tools/functions to clear the levels.
It’s not really a bug; if you know about some later level and decide you want to play it, either to playtest it and give us feedback or just to skip ahead, feel free. (Sometimes the pacing is too slow for some players, especially in the beginning.) Now, you may not be able to do them too out of order because you don’t have the gear or programming knowledge to do them, so beware of difficult levels.