Hey Jason, thanks for sharing your map. First of all, I would recommend you use a file name which does not include spaces, and only lower case characters, such as castle_gate.gbm, since this will solve problems you may otherwise run into with compatibility across different operating systems.
This seems to be a 2vs6 map, which is a rare concept, but can actually make a good addition this way.
The labyrinth on top is funny, but sadly AI will never make it to find the 2 player team this way. And even when all players are human it will show things down considerably as in bad performance (since your units still try to find a way to the enemy automatically once they spot it).
There is also a huge load of gold on this map, too much in my opinion.
This said, I like the 2vs6 concept, but please make sure you actually test your map and that all CPUs are able to find the opposed team.