Sea battle map looks nice, but what if the players fall of the ships?
They die. No really, there's no force fields or anything in that map so I find the idea of being able to fall off into death due to bad footwork or bad parkour an interesting concept. Didn't really care too much the other two, but last I heard the maze map was going to be made smaller so I think it's still a viable idea.
As people have stated in-game, I didn't really know the theme or the point of the farm map other than running into each other and occasionally into bumpy hills. My natural inclination to explore just wasn't activating in that map, there didn't seem to be much of a point going here or there when running into each other in the open field where each team spawned provided the same gameplay. I would like to use Tydeus's village river map as an example to draw inspiration from should you need it. In the center of the town you had a place for archers to arch, to the left of it you had an open field for cavalry to cav, and the north of it where the other team crossed the bridge provided a focused part for all types of people to do battle in. Not to mention the fun underwater fighting.
Basically what I'm saying is put some more thought into what you want people to do in certain areas of the map, otherwise it's just a generic field map.
All in all though, not a bad foray into map making considering you only just recently discovered the map editor and only spent a few hours in it. If you're still taking suggestions, I did like the dangerous footwork concept in your ship map very much and would like to see more bridge-intensive battles where backpedallers better learn to parry lest they like falling off things. Was a breath of fresh air gameplay-wise.