Planet Earth is genuinely easy. Science Lab is not. After working through all 60+ worlds, here's an honest difficulty ranking. "Difficulty" here means vocabulary obscurity, not puzzle mechanics — the grid works the same in every world.
Easy — you'll solve most clues from memory
These worlds use everyday vocabulary and common knowledge topics. If you speak English and have basic general knowledge, you'll breeze through most clues without help.
- Planet Earth — Nature, geography, everyday words. The best starting world.
- Seasons — Weather, holidays, seasonal activities. Very accessible.
- Farm — Animals, crops, countryside life. Simple vocabulary throughout.
- Pet Shop — Common animals and pet care. Few surprises.
- Sports — Major sports, famous athletes, game terminology. Approachable unless you're completely unfamiliar with sport.
- Circus — Performers, equipment, acts. Colourful but not obscure.
- Home Sweet Home — Household items, furniture, domestic activities. Everyday vocabulary.
- Dogs / Cats — Breeds, care, anatomy. Relaxed pacing.
Medium — you'll occasionally need pattern search or a hint
These worlds require some domain knowledge. You'll know most clues but will hit a few that need the grid's crossing letters or a quick lookup.
- Culinary Arts — Common cooking terms are easy; specific regional dishes and techniques get harder.
- Transports — Cars and planes are fine; obscure nautical and railway terms catch people out.
- Inventions — The famous inventions are straightforward; niche inventors and technical terms less so.
- Wild West — Well-known western culture; some historical specifics require knowledge.
- New York New York / London / Paris — City-specific knowledge. Easier if you know those cities well.
- The 80s / The 70s — Pop culture; easier if you lived through those decades.
- Popcorn Time — Films and cinema. Broad range from blockbusters to classics.
- Airport / Cruise Ship — Travel vocabulary. Occasionally technical.
Hard — expect to use pattern search regularly
These worlds have denser domain vocabulary. You'll know the topic but the specific terminology requires either deep knowledge or assistance.
- Ancient Egypt — Pharaohs, gods, archaeological terms. Plenty of obscure proper nouns.
- Medieval Times — Feudal titles, weapons, architecture. Specific vocabulary throughout.
- Art Museum — Painting techniques, art movements, artists' names. Highly specialised.
- Fauna and Flora — Species names, biological terms. The scientific names especially.
- Concert Hall — Musical theory, composers, instrument names. Hard without a music background.
- Greece — Mythology, philosophy, historical figures. Dense with proper nouns.
- Fantasy World — Mythological creatures, magical terms. Eclectic and unpredictable.
- Professions — Job titles get obscure fast beyond the obvious ones.
Expert — you will need help on multiple clues per puzzle
These worlds use specialised vocabulary that most players simply won't know. There's no shame in using pattern search heavily here — that's what it's for.
- Science Lab — Chemistry, biology, physics terminology. The hardest vocabulary in the game.
- Making a Documentary — Film production terminology and real-world documentary subjects. Very specific.
- Sense of Smell — Olfactory science, perfumery, scent classification. Unexpectedly obscure.
- Tundra and Taiga — Arctic ecology, species names, climate science. Niche vocabulary.
- Odd and Imaginary Creatures — Mythology from many cultures. Requires broad folkloric knowledge.
- Taking Care of Our Planet — Environmental science terminology. More technical than it sounds.
The honest advice
If you're new to CodyCross, start with Planet Earth, Seasons, or Farm. Complete those fully before moving to harder worlds — you'll build intuition for how clues are phrased that transfers across all difficulty levels. The clue-writing style is consistent; only the vocabulary changes.