Here is the full list of all 20 I've Seen Everything achievements.
Enter main menu
Win in the "Actors" category
Win in the "Actresses" category
Win in the "Animals" category
Win in the "Astronomy" category
Win in the "Dinosaurs" category
Win in the "National emblems" category
Win in the "Fishes" category
Win in the "National flags" category
Win in the "Fruits and vegetables" category
Win in the "Minerals" category
Win in the "Musical instruments" category
Win in the "Mythological creatures" category
Win in the "Painters" category
Win in the "People of historical importance" category
Win in the "Singers" category
Use hints for 100 times
Use anti-hints for 100 times
Use bonuses for 100 times
Finish the game with full heart supply.