Everything you need to know

Dark Watching was made by alessio that is now 15 years old but at the time on the steam release he was 14.

Ending one

To reach the first ending (also known as the main ending), simply follow the normal path and take the path to the elevator in the middle of the game but not the one "alarm door." path then Continue the story, and you've made it.

Ending two

For the second ending, you MUST NOT die after the lab. In the final chase scene, a wall is missing after the door explodes. Run through it and grab onto the wall opposite the holes.

Secret ending 

When you first encounter the Watcher and he tells you to leave, simply walk back. After a while, a cutscene will trigger and you'll unlock the secret ending.