Grid Wars has absolutely no connection to Geometry Wars. Or GridWars, for that matter.
The file GWRes2 includes a single string resource, "Hello", which is a message from programmer Roy Harvey:
For any hackers in the crowd, I have included the resEdit templates so you can play with some of the Grid Wars data... RPH - 08/17/85
True to his word, the file also contains TMPL resources that translate the hexadecimal soup of the game's level parameters into a series of forms that you can fill out from within the resource editor.