I made a quick try too, to save time using the compact oldgames.ru RIP release. Again for me too I couldn't notice any mouse severe problem, but instead I got other problems:
- the game window is forced to be borderless and doesn't release the mouse control
- the scene has huge clipping problems that I couldn't get fixed using the usual tricks on the Z-buffer settings. The enemies structures are always visible, even if behind a hill. This doesn't seem to happen for the soldiers, so there must be some specific problem.
- when entering the 3D mission screen I only see a black window until I Alt-Tab out and in again.