A couple week ago, I tried Fluxbox and it's really awesome. I installed this in my Termux and explore the complete GUI version through a vncserver.
Follow these steps if you want to do the same: https://wiki.termux.com/wiki/Graphical_Environment
Now, I can use almost all the linux tools in my phone. But, one thing is to be considered. As this is the graphical interface of Termux, we can only use termux commands here.
To explore the complete linux system, you have to install a distribution inside your Termux Emulator.