The map is very dark! You want to light up the playable parts of your map, even if it's supposed to be night, as it's very hard to see team colors and players when it's too dark. This makes it frustrating to play on the map.
Use some light_spots (some some basic light entities) around the map to light up where players are playing. There doesn't even have to be a lamp post or something for the light to come from, just the light entities themselves will do.