A few months ago I read at MakeUseOf that there are a few Online Mystery Games to check out. So, I’ll be sharing them with you… just in case

Sleuth

Make Use of says:
Sleuth (Shades of Mystery) is a series of open-ended, point and click detective role playing Flash games where you solve mysteries by searching for clues, interrogating suspects and interviewing witnesses. You start by creating your detective and his background. Your choice also determines the skills your detective avatar will bring to the mystery case. You can go through a tutorial training or jump straight into the case. You go into the crime scene and pick up clues. The goal is to pick up incriminating evidence and use deductive skill to accuse and charge the suspect.

I got stuck midway into the game. The detective game site also has a paid subscription plan which unlocks more benefits like other games and also the number of games you can play in a day.