1. Introduction of the game:
Five Nights at Freddy's: Help Wanted is a virtual reality horror game that forms part of the popular Five Nights at Freddy’s (FNaF) franchise. Developed by Steel Wool Studios and published by ScottGames, the game is designed to be a terrifying immersive experience where players must survive encounters with animatronic characters while solving puzzles and uncovering the dark mysteries of the series.

2. All characters and levels of the game:
The game features an array of infamous animatronic characters from the franchise, including Freddy Fazbear, Bonnie, Chica, Foxy, and many more. Each character brings its unique behaviors and challenges. FNaF: HW presents a compilation of classic levels reimagined from the original games, alongside new experiences specifically crafted for VR. Players navigate through a variety of levels, which are divided into different sections such as Parts and Service, Vent Repair, Night Terrors, and Dark Rooms, with each offering a distinct gameplay style.

3. What attracts users most to the game:
Users are most attracted to the intense and spine-chilling atmosphere that the game delivers through its VR support, immersing players in the eerie environments. Additionally, the game's unique blend of psychological horror, jump scares, and intricate lore keeps players engaged, as they must remain vigilant and strategic to survive the nights.

4. Why it is popular:
Five Nights at Freddy's: Help Wanted has gained popularity due to its association with the highly successful FNaF franchise, which already has a large fan base. The transition to VR adds a new layer of engagement and realism to the horror experience. Moreover, the game's challenging puzzles, hidden secrets, and the overall nostalgia for fans of the original titles contribute to its popularity.

5. When the game was released and how many versions are currently available:
Five Nights at Freddy's: Help Wanted was originally released on May 28, 2019. The game is available on various platforms, including PlayStation VR, Oculus Rift, HTC Vive, and Valve Index, with flat-screen modes provided for PC and consoles. Additionally, a non-VR version has been made available to cater to players without VR setups. As of the knowledge cutoff date, the game has received several updates and patches.

6. The most difficult part of the game:
The most difficult part of the game varies from player to player, but generally, it is considered to be the “Nightmare” modes and harder levels that not only require quick reflexes but also demand strategic planning and a strong familiarity with the animatronics' behavior patterns under increased pressure.

7. Strengths and weaknesses of the game:
Strengths of FNaF: HW include its immersive VR gameplay, the innovative reimagining of classic FNaF elements, and an impressive variety of levels that sustain the horror experience. The game also boasts a meticulous attention to detail and Easter eggs that enrich the lore. Conversely, the game's weaknesses may lie in its potentially overwhelming difficulty curve for newcomers and occasional technical glitches that can detract from the immersion.

8. What other games have been developed by the same developer:
Steel Wool Studios, the developer behind Five Nights at Freddy's: Help Wanted, has worked on several other projects including "The Horus Heresy: Betrayal at Calth" and "Bounce." Moreover, they continue to be engaged with the FNaF franchise, having developed the subsequent installment "Five Nights at Freddy's: Security Breach."