I'm guessing you're referring to the ability to filter out completed puzzles from the archive? I added it for logged-in users first because it was simpler but I can extend that feature so it's available for everyone. (I'll need to add some alternate logic to pass your indexeddb levels to the server endpoint when fetching the archive. It's not complex. I just haven't prioritized it yet.)

I'll add this to my backlog and try to get to it after the player puzzles release.

Beyond that everything is available regardless of user account right now. I do plan to require an account to submit custom puzzles when that's released. (Mostly to make moderation easier. I may relax this down the line.)

EDIT: On further thought I realized it's also required to have an account to view and share your profile stats, though that could also work without an account with some changes.