I played the three games of the series in sequence. This game references some events of the previous games, but you won't miss too much without playing them because the story is not an immediate continuation and even abandoned some plot lines left unresolved in the second game. In fact, I don't even recommend playing the first two games. They were awful. The developers somehow managed to turn the series from a total disaster into an excellent game. They themselves list the typical players' grievances with the previous games, putting these words in a mouth of a character who went mad.
The adventure of the third installment is just as wild as before, but its tone is a bit more mature, serious, and darker. The graphics and animations are much cleaner and improved. Surprisingly, the mouse controls are clunkier, but now you can also use keyboard. While the first two games should not be played without a guide, this game communicates well your overall objectives and the puzzles are much more logical. You can figure them out yourself without much frustration and mind-numbing brute force. If you get stuck, you can access a friendly helpline who gives a vague hint. Much more importantly, the dreadful pixel hunting that plagued the first two games was mostly eliminated. There are occasional objects that are behind other objects and aren't even visible on the screen. Thankfully, we got a button to highlight the active spots now. Still, there is no indication for where you can move between different parts of the same room, so you must try clicking on the sides of the screen to check for unlabeled locations.
The technical part of the game is solid, there was no need for extra steps to make it run. I encountered only a few broken animations and voice lines in the last chapters.
Overall, I recommend the game at full price. I was thoroughly entertained by the story and enjoyed solving the puzzles.
