Please give me a little feedback

This game certainly has potential, but has quite the way to go. Controls are somewhat minimal along with models and other assets being pretty basic, but being a beta it's a base to build from.

~ The truck model can use something more fit to underground digging.
~ Textures can be improved.

~ Controls can be improved upon.

~ Maybe use natural disasters to cause tunnels to fall and new resources to appear

~ Upgrade system for the digging machine.

The ideas can go on and on with a game at this stage. I'm just throwing some ideas on the table. :)