Is there a way to change the window size?
Solution 1:
There's no option to change the size of the window arbitrarily, although you can make it fullscreen. There are several fullscreen options, which involve different methods of scaling and handling aspect ratio differences.
Solution 2:
You can do this by editing the settings.ini file.
Set: manual, windowed and stretched to 1
Then you can set screen_X and screen_Y to whatever size you want.
For example:
manual=1
screen_x=640
screen_y=360
windowed=1
stretched=1