I like the general layout, but I noticed some immediate problems.
1. Too dark. I have my gamma settings increased, but not everyone does. It looks okay on my end, but some players were saying that they couldn't see very well.
2. Limited spawn points. As far as I can tell, you only have one spawn point (or area with a clump of spawn points) right in the middle of each base. That makes it incredibly easy to take over a base and just spawn camp. Especially because....
3. There are too many resources in base. It appears to me that this is a common mistake among beginner mappers. Gaining resources should be somewhat of a challenge on the map, or else the gameplay suffers. This map has a ton of mega armors and mega health in base, and multiple nexes and TONS of machineguns. Then you get to the middle channel of the map and there is a quad AND a shield AND mega health AND mega armor. There's just too much stuff available. The resources should be spread out a bit and there should be smaller items (ammo instead of weapons and small health instead of mega health).
I do like that you put the powerup in the middle area so there is something to fight over. I generally don't like having two powerups on one map, but that's just me.
I think this map could be refined and turn into something good though
