After finishing the Mystery Case File (Prime Suspect and huntsville), i'm looking for the similar game and i never got one, until yesterday when i browsed BigFishGame and i found an interesting game which i thought will be like the MCF series and it was called Hidden Expedition. It's the no. 1 hit game on BigFishGame, so i'm curious about this game, so i tried to download it and play the trial version of the game (trial version is limited to 60 minutes of play, but if you're quick enough, you can finish half of the game).
The game was more complicated compared to MCF, because your time was very limited by the oxygen that you had (mostly if you use the hints which will reduce your oxygen suply). Luckily there's an option to extend your oxygen supply by finding the oxygen supply icon which will add your supply a little bit. There's also some gems to be found, but i don't know what's the advantage of collecting this gems. After you collect all the items, you will face an extra task which has three variations as far as i know. The first task is collecting all the gems, the second one is completing the puzzle (some kind pictures), and the third one is collecting another set of someone's belonging. For the first and third task, your time will be very very limited as you will use the remaining time after collecting all the items, so sometimes it's very very hard to finish the last task because mostly you will run out of oxygen/time.
Last night i managed to complete 7 dive and i'm looking for more today. If you are curious, here is the screenshot: