Alright, so i see that upon starting people dont understand what to do, so here's little guide:
Your task is to find exit. How? Find a vent on a wall, it has red light, so you shouldnt have problem finding it. To climb on it you need a ladder. Where? While exporing a place you can find a locker. There's a ladder. And here you go! use ladder on vent (Point your cursor on it while having ladder) and u escaped. Congrats.
That was explanation of Easy mode. I dont think that im gonna need to explain all puzzles, so goodluck!