Here i have a demo of your map, so you can see how others play it. It is a first time playthrough.
liked it: it has some good looks and lighting, and plenty of ideas added and detail to it. The combats are not tedious or unfair, and the secrets are well done. It is also good to see that you put the effort so the map does not require any special engine or mod.
On the other side, it seems that you put too much attention on adding detail and not on detailing the map itself: Putting more work on making the rooms' general brushwork and composition, combats and layout themselves more detailed and varied would have worked better than adding lots of details to blocky rooms.
- The combat are a bit too straightforward and need some surprise or ambush, or just use the T intersections to throw enemies to the player from both sides.
- Some more variety in scale of the rooms.
- The way to the NG is probably too hard, save for speedrunners. As you set it up to make lots of damage it needs also a green armour or megahealth with the NG, at least on skill 0 and 1, and make the pipe on diagonal a bit bigger.
You need to give also a clue to the player that the slime is so harmful. Maybe a message and use another slime texture.
- Some doors need to be set up so they last longer open or stay open (wait -1 on the editor). For example, on the start map, as the player cannot hear what the door opened from there and the door itself has no message, it is hard to guess it is related to the beginning, even more as that side room resembles the ones on SoA expansion pack start map.
- Some doors are a bit hard to navigate and would need some clip brushes.
-It is too easy, save for the NG part or in skill 0. I would recommend to spice up the encounters or to set them up so the enemies do not aggro till the player is inside the rooms. The number of enemies is ok.
- Make it harder than the rest from the endless pit onwards.
To summarize, i would focus on spicing up the combats, fix some of the doors closing and the NG part, and yo would be ready to release.