All levels on Game Development locked

All of the levels on the Game Dev island are locked. Do I need to finish some other levels?

You need a subscription I believe.

which one? because I have beat one of them without a subscription.

Those levels were in “adventure” mode, that’s why they were available without a subscription. Now they are “premium” and you need to buy a subscription to get access for all additional levels. (https://codecombat.com/account/subscription)

Um, well there might be a problem. I can still access them. I just opened “over the garden wall” without a subscription .