Completely disagree with APulse, althought he is right in that every player skill are different, one of the basis of mapping is enjoy your maps yourself, so if you can't AGD or SR your own maps then that's a bit incoherent. Also, the only way yo make enjoyable and fun maps is being able of complete them yourself, whatever the skill level of the player, of course will be based on the skill of the creator, but at least be manageable, it is useless to do something that you yourself can not complete, certainly it's necessary for the rest to enjoy, or at least to improve yourself and create better gameplays with the pass of the time.

although it is good to stick to neutral by default, until your style and skill starts to vary.

And no problem, glad to help ;)

that #4 only falls in the category of preference since everyone's skill level is not the same

1-In your maps, try to focus on a solid theme. This map has a good theme of mushrooms, but it doesn't go much farther than the tileset. The object environment seems to have too much enemies, and be a bit random. Mainly-gausses seems to be a theme that would fit in this map, or mainly-rockets.

2-After you think of a theme, like I said, try to make the objects fit. Sticking to one or two types of enemies is best. Don't think that shoving a million enemies into a space makes the map better. Gold should be placed in delicious patterns that are enticing, but not over done. If you want to see a gold rhyme I made, check out the description in this [nmaps.net] map. Also, mines should provide structure, but not get in the way.

3-Playtest! Like zoasBE says, always AGD(all gold demo) your map before releasing. Anything too hard or easy should be fixed, which leads us to #4

4-Difficulty should usually be neutral, unless you want to make a purposely easy or hard map. Mine-jumpers are usually harder than normal, so take that into account. Remember, you want the player to enjoy it, and be slightly challenged.

5-After play-testing and editing, make a final run-through of the map. Is everything layed out well? Do the objects compliment the tileset? Try to picture the map as a thumbnail. Are the mechanics of the map fine-tuned? Are there unnecessary areas or items?

Here are some maps that seem to do what I just said. Also, check out astheoceansblue (or atob) maps. He works well with gameplay, and provides mapping tutorials.

http://www.nmaps.net/174363
http://www.nmaps.net/170549 (read first comment)
http://www.nmaps.net/223332
http://www.nmaps.net/226113
http://www.nmaps.net/226582 (hard one, but sticks to a theme)
http://www.nmaps.net/225512
http://www.nmaps.net/225117

and many more...


Hope this helped :D
I barely proofread this...

it gets a bit messy otherwise

You seem to be getting the hang of NUMA already, and your maps are getting better!