I would start to check if a linear change of (e.g. the enemies speed) solves the problem:
[edit: I would try to solve it by changing just one parameter unless I get no good results]

Starting with the default ratio (4/3) I would calculate the ratio between the widescreen-ratio and the default screen-ratio:

e.g. 4:3=1.33, 16:9=1.77 => 1.77 : 1.33 = 1.33 (ratio-factor)

Now I would multyply the enemies speed with the ratio-factor and a constant (to change the power of the ratio-factor).

I would test this by setting extreme monitor-aspects (with video_set()) and play with the constant.


If all this returns no good result I would try to use non-linear methods (edit: or change more than one parameter with this ratio-factor).

mercuryus