I like to play at a reduced speed so that I can think about things more, and I've noticed something slightly odd: When the game is slowed down to, say, -10, things don't just go slower, but also become more choppy, as though the frame rate was going down. You can see the effect clearly by looking at one of the rotating planets in the background. At speed +0 the rotation is smooth, but at speed -10 the rotation becomes choppy, though the actual net speed of rotation seems the same. Ship movements are similarly affected, to the point where a fast ship flickers noticeably when the game is set to slow time. It's as though the animations are being displayed with the same number of frames at a slower rate.
If there's a UI rewrite at some point, it seems like it would be better if the game speed adjustment tried to maintain a constant frame rate, drawing more frames per inch of movement at slow speeds, and fewer at high rates. This also might help improve performance when the game is sped up.
