1. Introduction of the game:
Candy Crush Jelly Saga is a delightful and engaging match-three puzzle game developed by King. As a successor to the renowned Candy Crush Saga, this game invites players to match colorful candies and jellies to progress through whimsically designed levels. The aim is to spread jelly across the game board or release Pufflers hidden beneath the frosting, adding a layer of strategy to the familiar match-three format.

2. All characters and levels of the game:
Players are greeted by the game's vibrant characters, including the mischievous yet adorable Jelly Queen, who challenges them throughout their journey. Joining the roster is Cupcake Carl, Puffler, and other delightful characters, each with unique personalities that brighten the gameplay experience. The game boasts hundreds of levels that get progressively challenging, each offering a variety of objectives and obstacles. As with other Candy Crush games, levels are grouped into episodes, and new levels are frequently added through updates.

3. What attracts users most to the game:
Users are often drawn to Candy Crush Jelly Saga for its eye-catching graphics, captivating special effects, and soothing soundtrack. The easy-to-learn-yet-challenging-to-master gameplay keeps players engaged for hours, offering a satisfying balance of relaxation and mental stimulation. The competitive aspect, such as beating the Jelly Queen's high scores or climbing the leaderboard against friends, also contributes to its appeal.

4. Why it is popular:
Candy Crush Jelly Saga's popularity can be attributed to its accessibility and addictive nature. It seamlessly combines simple game mechanics with increasingly complex puzzles that require strategy and forethought. Its connection to social media platforms makes it easy to compete with friends, driving its viral status and community engagement, which are hallmarks of King's games.

5. When the game was released and how many versions are currently available:
Candy Crush Jelly Saga was first released in April 2015. Since then, it has been updated numerous times, with new levels and features added regularly. While there is only one base version of the game, its updates can be considered as different versions since they often bring substantial changes and additional content.

6. The most difficult part of the game:
Many players find the boss battles against the Jelly Queen and other characters to be particularly challenging. These levels require a blend of strategy and luck, as players must carefully plan their moves while coping with the unpredictability of the game board. Additionally, certain levels with limited moves and complex obstacles can prove to be quite a hurdle even for seasoned players.

7. Strengths and weaknesses of the game:
The game's strengths lie in its captivating graphics, diverse level design, and the strategic depth added by unique game modes and character battles. However, some may view the in-app purchases and reliance on microtransactions to unlock additional moves or lives as a weakness. The difficulty of some levels might feel artificially inflated to encourage these purchases, which can be a point of frustration for players who prefer a free-to-play experience.

8. What other games have been developed by the same developer:
King, the developer behind Candy Crush Jelly Saga, is famed for creating other hit titles in the Candy Crush series, such as the original Candy Crush Saga, Candy Crush Soda Saga, and Candy Crush Friends Saga. Beyond the Candy Crush franchise, King has also developed popular games like Bubble Witch Saga, Farm Heroes Saga, and Pet Rescue Saga, among others. All these games bear King’s trademark of accessible, addictive gameplay with colorful and engaging themes.