The groups are as follows:
A: Anagrams of greek letters
B: Words with two sets of double letters.
C: Words that begin with US president names.
D: The position (in the alphabet) of the first letter determines the number of letters in the word. I.E., ‘d’ is the 4th letter in the alphabet, so the word would have 4 letters in it.
E: Words which contain all the vowels
F: Every letter of the word is in alphabetical order.

Once you have completed the correct answers to the clues, if you align the puzzle pieces to the grid you get the red and blue box layout shown here. Unscrambling the blue boxes yields “TOP CARD” and unscrambling the red boxes yields “SEVEN”

Once the cousins are placed (yellow circles) read out the letters they are placed on from top to bottom left to right. “COMPANY THAT CREATED MARIO” The answer to this is Nintendo.

Now that you have all the words annd numbers from the previous puzzles, and the order in which they are relevant from the picross grids, use that information to get what you need out of the High Score Sheet.

1. Picross grid 1 revealed that the first digit is the Tetrominoes puzzle.
   • Tetromonoes clue "TOP CARD SEVEN" should be referenced on the High Scores sheet.
   • You'll find that "ACE" is a player name and the 7th digit on that score is 6.
   • ACE is the top card in a deck.
2. Picross grid 2 revealed the second digit is the Word Invasion puzzle.
   • Tetromonoes clue "TOP CARD SEVEN" should be referenced on the High Scores sheet.
   • You'll find that "ACE" is a player name and the 7th digit on that score is 6.
   • ACE is the top card in a deck.
   • The clue for Word Invasion was "Rouge 4."
   • You'll see "RED" is a player name on the high score sheet (rouge is a shade of red)
   • Take the 4th digit from this score
3. Picross Grid 3 revealed Jumpman to be the 3rd number.
   • The clue for Jumpman was "TOKEN ONE"
   • You'll find 25c as a player (a 25C token)
   • Take the first number from this high score
4. Picross Grid 4 gives the Pac-Security puzzle is the fourth digit
   • The clue for this puzzle was ninTENdo
   • You'll find "NES" is a plyaer name
   • Take the 10th digit.

Given all these clues you should have the below answer: