Yeah, I think I snagged Horses from the new world (my primary reason for fighting BGN) as you were sailing to Pong , so I pretty much whipped my cities to the nub on HA's with the intent of getting it back for some kind of moral victory. That city had been untouchable for so long that I didn't even plan for an Astro invasion -- I got complacent there. At 80% defense, I could have planted 3-4 G3 Longbows and likely kept it despite your formidable stack.
Also you may not know but the turn before you took Pong, I had just retired a GG there giving me 4 promos by land and 3 by sea. It wasn't going to do much in the long run, but certainly would have bought me a few more turns if I got to use it.
My 3 favorite moves of the eastern theatre:
--taking out one of your roving EI's with a small fleet of 4 ships in a last hurrah. There was nothing much else they could do. The victor was promoted to Nav2, which allowed me enough movement to safely shuttle some troops to the mainland with a stop in Asteroids.
--the decimation of your stack outside of Krull on BGN's island, as I did leave some units behind to defend there from my stand off with BGN. The pisser with that one is that I had an HA ready to build there next turn, and for some reason switched it to a Cat the turn before to see if it could be whipped. Never changed it back -- otherwise I think you would have only been left with one unit. Oh well.
--blocking your second arrival at Pong by moving some units to the fort canal I had built for you earlier lol. I had a feeling you had at least one EI just waiting to coast into Pong with some defenses, and I looked to be right. This allowed me just enough to retake the city.