Most flash game are static. Playing through them differently usually doesn't lead to different results(other than maybe a higher score). FNAF antagonist study your habits every night and react accordingly.
In the first game it is them, the camera, the power supply and the doors that you have to worry about.
The second there is no door, but you are still limited on power and this time they can crawl through vents and disable your character which in most cases is a game over.
In the third, you no longer have to worry about power or a flashlight, but the electrical systems are faulty, will fail and you will need to reboot one or more of them at any given time, on top of having to keep the animatronic away from your hallway.
It is a point and click yes, but it simply isn't clicking here and there for results, it is about developing patterns, and strategy in order to combat increasingly aggressive AI, not becoming predictable but having to anticipate your enemy's moves in return.