Hush!

Hush and make your way out! Don't walk fast for too long. Squat down and move on your tiptoe, otherwise, you will be noticed!
NOTE: use full screen to have smooth control of the view.
The online version may be laggy, here is also a full playthrough.
https://www.bilibili.com/video/BV1y64y1D73s/?vd_source=f59cedb06a94a5f5dd5c2c0d1...

CONTROL:  Mouse and keyboard. Space to jump, Shift to squat down, F to switch from pull/push the red box.