okay fine... it was good.
But in all actually, the movie did a very good job in giving a character to mike. he is no longer just a name we see on the check/termination papers, the movie gave him a personality and a background. for fans of the game, there are many easter eggs and important lore that makes the movie all the more enjoyable if you know the story.
For those who did not grow up playing fnaf, i do not think you will enjoy the movie as much. There is so much lore and it is already confusing and the movie did a great job as to not introducing new pieces of lore as to not confuse long time fans.