I read the second version of the rules first, never having seen the
earlier version or read the mailing list, so I'll offer a perspective
on learning the game from just that information. It's hard. The
general rules are pretty easy to understand, but several aspects of
the individual rules took several reads to understand.
First, the terminology is inconsistent. How do up, down, forward,
backward, and upstream relate to one another? I saw some concerns
about "right" and "left" mentioned on the list, but I think those
could be okay substitutes. Alternately you could use "east" and
"west," which would handle the note about the lines being parallel
nicely, I think.
Tip, Aim, and Wild are fine, terminology aside.
I guessed the right meaning for Swap, but it was ambiguous until I
read the older rules. I like the suggestion from the list: "Pick two
pieces. Trade their positions and orientations."
Hop confused me at first, but it turned out I was just overlooking
the general rule about gaps forming as needed. Once I saw that all
Dig is by far the worst. I'm still not sure I understand what's
intended with this rule. What's "upstream?" "Between" a piece? My
best attempt at a paraphrase, given my understanding: "Move a piece
any distance in the direction it's pointing (or not at all) and stand
it upright. If it ends up below another piece, turn that piece
upright if necessary."