I just tried your map - quite possibly the best map of its kind so far. Here's the good:
- The terrain looks flawless, and i like how you've incorporated sound in many ways.
- The quality of the music is great.
- Siege AI is a huge plus.
- You had plenty of in-game hints. Too bad some of them were too late (like the gimli/aragorn gate barricade hint).
- The pathing seems to work very well.
And here's the bad:
- Some heroes have very few active abilities. The elves, specifically, have one at best. While this was handy for me when playing alone, i can imagine it would get boring in a 12 player game.
- Most of the abilities were rather plain, vanilla spells. Gimli was essentially just a reskinned mountain king. I wish you could add some more colorful custom ones with cool effects. The ones i think you should keep are: Summon Rohirrim, Multishot (passive), Kings Inspiration, since these are useful. For the rest, just try playing some AoS maps to get good ideas for spells. I can recommend "Monolith", it has very creative design.
- Again, the shops inside the keep are a bit camouflaged into the scenery, and i actually forgot about using them at all.
- The camera doesn't keep its position if you zoom or spin it. You should have a periodic 0.03 second timer which sets it to a distance and rotation specified in a variable for each player, and update this variable everytime you want to change the camera range or rotation.