Change the terrain even more.
It needs to be amazing.
You need to add a lot more units/buildings (make it so you can select which unit spawns from a building, so there are multiple units in the same building).
When that is done, you can improve the triggers:
Make them more efficient and make them work correctly
Remove the leaks
Make a nice multiboard
When that is done, you can start thinking about expanding the features... some game-modes perhaps, a hero (or heroes), custom spells, a few systems, that's up to you.
And when the map is finished, read my tutorial about the description and make a really nice description in-game and on the hive.
The description is the first step to attract users... never forget that.