Final said:
Of course, it needs a limit. Like ten iterations.
Given that this is only possible through surface duplication, it would follow that an alpha channel would be necessary else iterations would be infinite anyway.
Given ten iterations with alpha channel, with manual drawing to leave out background.
Multiplied by FPS...... 300 times per second.
I think you'll understand what I meant by my comment now.
Drawing a whole surface, let's just be generous and say 1ms lag.
It would be somewhere much higher, but let's go with 1ms.
Gives 300ms lag every second.
Not playable at 0.7x speed.