What device do you use? Because in my tests the fangame runs pretty well on both my phone and laptop, so the maps might not be running well for you if you are using a low end device, and if that is the case, keeping your device plugged in while playing should help improve performance.
In V1.01, I plan on making it so the office is hidden from rendering while you are on the camera system (and a pause menu is getting added to the each location as well), which should improve the performance while the camera system is open or the game is paused.