It's not necessarily a crime, but it's going to reduce the level of interest. Especially for fullscreen users. Since in Windows 7, there's no way to have fullscreen resolution below 640x480.

So, if you limit the screen resolution to 400x300 [Just an example], then the game will be letter boxed or whatever it is called, since the game will still render at 640x480p and because of the way this game works- it won't scale the screen. It will have black box and the screen will become small.

So, yeah. Forcing won't do anything good. Best thing to do is to recommend the screen resolution in readme file.

Also, the LCD sucks in scaling non native resolutions. Only way to have clear screen is if it's dividable by 2.

For example, in my 1440x900 monitor:

1200x900 will look good, if I maintain the aspect ratio and have black bars at the sides of screen.

600x450 will look good, if I maintain the aspect ratio aswell. [Which is 4:3]

720x450 will work without any tweaks in aspect ratio. Since it's a 16:10 res [Which is the aspect ratio of my monitor]

1440x810 will look good, if I have black bars on top/bottom [16:9]

720x405 will be fine too.

Other resolutions will look ugly as shit in this monitor. Unless if you have big ugly black bars around it and make it small.