Immediately upon loading, and during splash screens, mouse cursor seems to convert from an Hardware cursor to a (larger) Software cursor and immediately fly up into the top-left corner.  Moving the mouse shows the 'primary' cursor (small, hardware cursor) respond appropriately, but glitches to include at least an half-dozen other cursors radiating from the original in a top-left trajectory.

This occurs despite the following:

1. changing from fullscreen to windowed mode, or fullscreen window mode (and back)
2. changing display resolution
3. exiting game and restarting
4. unplugging and replugging/trying different input devices
5. attempting to use keyboard controls
6. somehow managing (by button mashing the mouse button) to navigate to another screen