1. Introduction of the game:
Discover a world of letters and words with "Words Crush: Hidden Words!", a captivating word puzzle game that challenges your vocabulary and cognitive skills. This game invites players to swipe and connect letters on the board to form words hidden within a grid, offering endless hours of brain-teasing fun. With its simple yet addictive gameplay, it's a perfect blend of relaxation and intellectual challenge suitable for both word game novices and enthusiasts.

2. All characters and levels of the game:
"Words Crush: Hidden Words!" has no specific characters, as it focuses purely on the gameplay. However, the game is replete with numerous levels, each categorized within stages like Beginner, Intermediate, Advanced, and so forth. Each stage contains multiple levels that increase in difficulty, presenting a satisfying progression for players as they advance.

3. What attracts users most to the game:
Users are most attracted to the intuitiveness and simplicity of the game that masks a surprisingly deep challenge. The clean interface, coupled with the satisfaction of finding all the hidden words, provides an enjoyable and rewarding experience. Furthermore, the progressive level design keeps players engaged, as they need to continually adapt their strategies to solve new puzzles.

4. Why it is popular:
"Words Crush: Hidden Words!" has gained popularity due to its accessible gameplay that caters to a wide audience. Its educational value, such as enhancing vocabulary and spelling, combined with the joy of problem-solving, appeals to both children and adults alike. Regular updates with fresh puzzles keep the game exciting and have cultivated a dedicated player base.

5. The most difficult part of the game:
Many players find the higher levels where the grids become larger and the words more obscure to be the most challenging. The difficulty spikes in these advanced stages require an extensive vocabulary and sharp focus, pushing players to their linguistic limits.

6. Strengths and weaknesses of the game:
The game's strengths lie in its simple yet engaging gameplay, educational benefits, and the sheer number of levels that provide long-lasting entertainment. However, some may find the difficulty curve too steep at higher levels. A minor weakness could be the presence of in-app purchases and ads that might impact the gaming experience for some users.