1. Introduction of the game:
Fortnite is an immensely popular online multiplayer video game developed by Epic Games, offering an exciting and immersive gaming experience set in a vibrant virtual world. It falls under the genre of a battle royale game and has captivated millions of players worldwide since its release.

2. All characters and levels of the game:
Fortnite features a diverse cast of characters, each with their own unique abilities and playstyles. Players can choose from a wide range of characters, known as "skins," which include imaginative outfits and accessories. Additionally, the game offers various levels, or maps, where players engage in intense battles and explore different terrains, ranging from cities to dense forests.

3. What attracts users most to the game:
One of the primary attractions of Fortnite is its dynamic gameplay and competitive nature. The game incorporates elements of strategy, survival, and teamwork, making it highly engaging for players. Furthermore, the constant updates and additions by the developers keep the game fresh and exciting, bringing players back for more.

4. Why it is popular:
Fortnite's popularity can be attributed to several factors. Firstly, its accessibility, as the game is available on multiple platforms, including PC, consoles, and mobile devices, allowing a wide range of players to participate. Additionally, the game's free-to-play model and the absence of pay-to-win mechanics have contributed to its widespread appeal. Moreover, Fortnite's vibrant graphics, quick match durations, and intense gameplay have helped it gain a massive following.

5. When the game was released and how many versions are currently available:
Fortnite was first released on July 25, 2017, with a focus on its cooperative gameplay mode, "Save the World." However, it was the introduction of the battle royale mode, launched on September 26, 2017, that propelled the game's popularity to unprecedented heights. Currently, there are multiple versions of Fortnite available, including the main game, "Save the World," and the immensely popular battle royale mode.

6. The most difficult part of the game:
The most challenging aspect of Fortnite lies in its skill-based gameplay, specifically in the battle royale mode. Players must navigate a constantly shrinking play area while combating opponents, building structures, and managing limited resources. Mastering the art of building during intense combat situations and developing accurate shooting skills are often the most demanding aspects of the game.

7. Strengths and weaknesses of the game:
One of the significant strengths of Fortnite is its engaging and immersive gameplay, offering a perfect balance between strategy and action. The addition of regular updates and new features ensures a varied and evolving experience. However, the game's competitive nature can occasionally lead to a steep learning curve for new players, and its reliance on internet connectivity poses a weakness for those with unstable connections.

8. Other games developed by the same developer:
Epic Games, the developer of Fortnite, has created several other successful games over the years. Some notable titles include the Gears of War series, the Unreal Tournament series, and the highly acclaimed Infinity Blade series, all of which have contributed to establishing Epic Games as a renowned and respected game developer in the industry.