Go into C:/Program Files/Gravity/RO/ (or where ever you installed)
And look for a file called setup.exe
Run that
*Switch to your graphics card (Intel 828 Integrated, ATI Radeon, etc), or switch to Direct3D, OpenGL if your graphics card is selected
*Switch from fullscreen to windowed, of if you're in windowed already, switch to fullscreen
*Don't use widescreen resolutions. Only use normal screen modes such as 640x480, 800x600, and 1024x768