Unironically great. Went into it expecting a laughably bad movie, only watching it to pay tribute to my childhood, and found myself enjoying the movie within the first 20 minutes. After that the movie flew by, surprising me that it was over after what felt like only half an hour. The beginning felt like I was watching some sort of spoof, but once the plot picked up, it felt like a comedy. The movie not going in a completely serious direction was an excellent choice.
The only thing I could criticize is how not all jokes appealed to me, but considering the movie was made for three distinct generations of viewers, newer young players, fans of the game since it's older days, and the parents, it was excusable. Although many there were many jokes or moments that didn't land right with me, I could recognize how it would be amusing or impactful to other groups.
Many criticize Jack Blacks personality being heavily implemented into Steve's writing, however I see it differently. The character of Steve fundamentally lacks personality, meaning this choice doesn't do disservice to the character and in my opinion, adds a lot to the movie.
This movie served my expectations well, and I appreciate the time and effort put into the film. It is now one of my personal favorite "video game movies".