I'm not sure what possessed Frogwares to release this abomination. Maybe someone was huffing their own farts too much. Maybe drugs were involved. Whichever the case, they need to stop.
It's not so much the investigation mechanics (although they are clearly a step down from "Crimes and Punishments" or "Jack the Ripper"). The problem is basically everything else. The character designs are bad. The dialogue is cringy. They decided to do an open world, but neglected to fill it with anything interesting (the side quests you get are rather boring), which makes exploration completely unrewarding. You get a gun, but of course you aren't allowed to kill anyone with it (not even in self-defense). Instead you use it to shoot armor pieces off your opponents to stagger them, so that you can "apprehend" them with Quicktime events.
On top of that all of the main story cases are ambiguous (there is no correct solution, you just pick a culprit). Last time I checked, that's not how Sherlock Holmes cases worked in the books or the games.
The sad thing is, the main story might actually have worked had they gone with an original main character. But pairing Sherlock Holmes, one of the most rational, logic-obsessed characters of all time, with an imaginary friend? And in his twenties no less? That's just mind-boggling levels of stupid.