No. Can you actually do that at OS level? IME if you plug in a second mouse, both moves the same cursor. So you should really reconsider this (how many people has a second mouse to play games?).
Now, with a touchscreen display using multitouch input is possible and much more common.
While this is unusual, it’s actually possible to achieve on OS level, at least on Windows for what I know. There are functions that seem to imply only one mouse is supported, but you can get two mouses to work if you use raw input:
I believe that most people do not use two mice because it is not given the chance to do and we develop do nothing to warrant the use of two mice. So I am investigating if possible because I see many useful things to do.
Jarcelo | 2016-09-16 13:04
Nevertheless, the answer is still no: Godot does not support two mice. I doubt there will be any official effort to do this, but as an open source project you can always propose a code change/addition.
vnen | 2016-09-16 14:22
Yeah but that would require some effort since it’s at OS-level and would require a different implementation for Windows, Linux and Mac