I've never read a Hardy Boys book, but I imagine this is supposed to be a parody of those.
The quick review for the movie is that it was terrible. What makes it even worse is that I can tell it would have worked with only a few minor adjustments. I'm going to blame most of this on the director.
Okay, the big joke within the movie is that we have a trio of former child detectives - did we ever get to see that? No. Would one scene of that, at the beginning, have helped level the tone? Yes - who are now in their late teens, yet have not shed the sweet innocence of their youth. Most of the jokes are coming from this place of how naive the boys are, juxtaposed with trying to solve a homicide. Great idea, but it got old fast, and almost none of the humor worked.
The biggest problem I had here was "the muscle" for the Mystery Team, Charlie. He is one of those characters who is painfully stupid, and too many times the plot relied on how dumb our characters are in order to move the plot forward. Again, in better hands, this could work.
Almost every other part was okay. Most of the cast does a great job. The dialog and the action is funny, but none of it lands. It's just sad a competent director couldn't have made this.
The highlight for me was Ellie Kemper - this was predating her role as Kimmy Schmidt, but she's basically playing the same part - even though she's only in three quick scenes.
Who would I recommend this to? I don't know, maybe millennials who thought _Napoleon Dynamite_ (2004) was too intellectual.