You could easily make 1.x work with even 9.x versions, when it was first released it was 10.0? if not lower.
But changing it into a 8.x version or lower would take alot of time for the simple reason, how they coded it.
0,2, 0,3, 0,4 are diffrent versions.
1.0 was based on 0.2.
Unless you want to spend atleast a couple of days of fully coding and checking the code you won't be able to do it.
The hardest part is the protocolgame due to it's lenght.