Fixation will keep you captivated and addicted at the same time. This is because it combines heavy puzzle elements with unique physics, as well as heavy dialouge that has a definate psychological meaning behind it.
Play as Kathryn, and go through dozens of levels of puzzles (using smoke and smoke rings from cigarettes to overcome obstacles, of all things!), dialouge, and fun. Kathyrn is having a hard time with life, so as you go on, it becomes more than that, it becomes a journey, and you think about what is going on, what all this means, unlike many other flash games.
I think you should find out for yourself what I mean, the game is one of the most worthwhile plays you could get for flash games. Try it out now on Kongregate for badges!