1. **Introduction of the game:**
"Mortal Crusade: Sword of Knight" is an action-packed RPG platformer that invites players to embark on an epic quest filled with danger and excitement. Set in a fantastical realm where darkness threatens to consume all, players wield the sacred Sword of Knight to vanquish evil and restore peace. The game combines classic RPG elements with exhilarating combat and platforming challenges.

2. **All characters and levels of the game:**
The game centers on the valiant hero, whose customization options allow players to create a unique warrior. Along the way, players encounter a variety of NPCs including allies offering quests and vendors providing gear. "Mortal Crusade" features a myriad of levels, each with distinctive environments such as haunted castles, enchanted forests, and treacherous dungeons, all teeming with formidable foes and bosses that test the player's skill and determination.

3. **What attracts users most to the game:**
Players are most attracted to "Mortal Crusade" for its captivating retro art style, fluid combat system, and deep RPG mechanics. The game's engaging storyline, coupled with the thrill of exploration and treasure hunting, keeps players immersed in its world. Additionally, the game offers a sense of progression and customization that encourages players to continually develop their character.

4. **Why it is popular:**
"Mortal Crusade" gained popularity because of its successful blend of genres, satisfying both platformer enthusiasts and RPG fans alike. Its challenging gameplay, nostalgic pixel art graphics, and dynamic soundtrack contribute to a memorable experience. It also resonates with gamers who appreciate meticulous level design and those who seek a genuine challenge.

5. **The most difficult part of the game:**
The most difficult part of "Mortal Crusade" is often considered to be the boss battles which require precise tactics and perfect timing. Additionally, certain levels have platforming sequences that demand exact jumps and quick reflexes, pushing players to their limits.

6. **Strengths and weaknesses of the game:**
Among its strengths, "Mortal Crusade" boasts a robust leveling system, a diverse array of enemies, and intricate level design. However, the game's weaknesses might include occasional spikes in difficulty that can be a barrier for casual players and a storyline that could be more developed to enhance the narrative depth.