In comparison to the manga, Kindaichi anime is slightly behind in the details as from a manga fan's perspective, the anime played well in building up the tension and the suspense, but lags behind when it comes to hinting the killer.
Overall though, the show is a good introduction to the Kindaichi experience as in plenty of the cases, especially when you rewatch, you can actually catch up the author's hints for how the crime was committed.
The Kindaichi franchise still goes strong despite its age and this series is a good example of why the franchise has a strong backing of loyal fans. Kindaichi Returns is also an adaptation of many loose cases in comparison to the original run, hence it's easy for viewers to just hop in and follow what is going on. I'd say if you do not have a way to follow the original run, Kindaichi Returns is a good way to introduce you to the franchise and understand why the fans are loyal to this series.
