USG40 to ZyWall IPSec VPN Client (windows 10) - can only ping router

Hello. We have a USG40 at my office.  A colleague is out of town and we need him to be able to connect to our network.  The idea is to use ZyWall IPSec VPN client on his Windows 10 machine and connect to the USG40 vía IPsec. 

I saw this tutorial and followed all steps exactly like in the video. 

The tunner opens fine, however, I just manage to ping or connect to my router, using the local ip on my remote machine. I can't connect to any other computer.

Please help!