Some users have reported interest in having the “Escape” key bring up the in-game menu instead of deselecting units. This can be accomplished by:
1) From Main Menu select Options
2) Click on the Controls tab
3) In the Selection section of controls find the “Cancel” command and bind it to a currently unbound key (key other than “Escape” )
4) In the Menu section of controls find “Menu” and bind the “escape” key
If you have any questions about this process, please submit a support ticket at http://support.gearboxsoftware.com.