You're not using any kind of random factor to control the sprites, then?
The enemies are not random, if that is what you are asking? I do record the seed so that if I do use a rnd function somewhere it does come out the same. It still isn't perfect though for some reason. For example, if I record a session on a computer and play it back on the same computer it usually works, but if i take that same file and play it on another computer, it will work, but the score may be off by a little bit, etc. I based everything on a frame count, but I think I may have stuff based on time somewhere that may still affect it somehow, resulting in slightly imperfect playback.