Having made it all the way through the 2014 show without issue, it was submitted into the 2015 show. On Saturday, the 2nd show day, the game backgrounds began flashing all green and eventually the background went all green leaving only the sprites displaying :(
The problem looked to be with the game board since the sprites were mostly displaying properly. I elected to start poking around with the scope at the output 4Q of the object data latch at L10 (LS175). In a stroke of luck that has never happened before this signal, the very first one looked at, was stuck high compared to the other outputs, it's compliment and input. Replacing L10 fixed the game :)