So I wasn't 100% happy with my KotMK entry, so I updated it...
now the invaders stay upright, and oriented towards the "player", and they have grey outlines, and the "chase cursor" is a bit different... now x+y axis is changed when you move the mouse, and x+z when you move the mouse with the button held down. Plus the chase box is a white box rather than a red dot

again, more of a toy than a game....