What I'm going to do is post daily screenshots of my current map right here in this topic. You will see structures being erected, sometimes wiped out, but often changed or tuned.
The working title of my current map is 'Necromancer'. It is 60% finished, so you'll see a few empty patches at first.
It already has some features you haven't seen before, amongst which are 'walking bullets' and a special type of 'timebomb', but you'll have to wait for the map's release to see these in action!
Estimated number of objects will be between 500 and 600, which will run smoothly on most computers.
There will be secret passages, traps, pitfalls, highways, tunnels and complex structures. It's also an assymetric map, meaning every corner is unique (and that it's a lot of work). Gameplay should be great when there are 6 to 12 players on.
Editing is fully done in a text editor, but I continuously use BZEdit to preview the map in 3D.
Of course, feel free to discuss the map in this topic
beware.....
, but you're right 
...and very observant. As a matter of fact, I planned the layout of Necromancer such that it would offer similar gameplay to Rat Lab, with an open space in the middle, an off-centre tall 'castle/pyramid', highways around and teleporters in a similar arangement. I did not choose to do this because of something trivial like a lack of imagination, but rather, since I'm very fond of the gameplay of Rat Lab (which in my own humble opinion is kinda smooth). However, all of the structures are unique and gamers should have a blast in it (or be blasted...whichever you choose).