Start by entering the items that belong in the first category. As you guess the answers in the first category, a code for a safe will appear. Type it in to reveal the following safe category. Make it to the end!
Neither are the rest in the category save Ireland. Today I learned "Celtic Nations" has a meaning independent of current sovereign states, I had to look this one up, never'd heard of it before
I typed mandarin and got Isle of man, from there i could Piece together that the clue should be celtic nations without getting all k countries, so maybe you should change one of the clues, or the type-ins