EC Puzzle Hunt/Cobble

Cobble is one of the opener puzzles from the first round of the EC Puzzle Hunt.

The puzzle's presentation is reminiscent of a cobblestone path. The word "ALPHA" is written at the start of the path, but otherwise it is empty. Like the rest of the puzzles in its round, it is entirely in grayscale.

Solve Path
The puzzle features a long path that is 5 cells wide and divided into multiple segments. The word "ALPHA" is written down in the first row. A link to a word list is also provided.

The puzzle is based on Wordle. With the color gone, however, a light gray cell represents an incorrect letter, a medium gray cell represents a correct letter in a wrong position, and a dark gray cell represents a correct letter at the correct position. With the flavor text suggesting connections, solvers should try to find other words from the same category to fill in. Beside the path, there are also minor clues to the categories, in the form on ???.

For the first section, "ALPHA", the category is "GREEK LETTERS", and the solution is "DELTA".

The solution to the first section will then need to be copied into the first row of the second section in order to solve it. However, we'll now need to consider a different category to which "DELTA" belongs (NATO ALPHABET). Solvers can now use this to solve the second section to get "OSCAR".

Solvers should keep going down until reaching the end: OSCAR -> CREED (CHARACTERS FROM THE OFFICE) CREED -> QUEEN (ROCK BANDS)

QUEEN -> JOKER (CARDS)

JOKER -> ROBIN (BATMAN CHARACTERS)

ROBIN -> CRANE (BIRDS)

CRANE -> FRUIT (FLIES)

FRUIT -> GRAIN (FOOD GROUPS)

GRAIN -> POUND (IMPERIAL UNITS OF MASS)

POUND -> ZLOTY (CURRENCIES)

The final answer is the 5-letter word that lies at the end of the path.

Puzzle Elements

 * Hint in Flavortext - The flavortext hints at finding words that share a connection.
 * Wordle - The puzzle is based on Wordle. The title is also a play on it.
 * Givens - The first word, "ALPHA", is the only word given.
 * The Waterfall Effect - The solution to each section of the path becomes the starting word of the next section, and is crucial to solving it (except for the final section's solution, which is the puzzle answer).