SCREEN SHOTS LESS = MORE?

I don't think the number matters all that much personally, as long as you have a reason for showing it.

And that could be all sorts of things. You could just be proud of it, you could be aiming to show one screen of every unique area (1 screen from town A, 1 screen from the forest area, 1 screen from the swamp area, etc), showing off unique features or points of interest, showing off a custom tileset--you get the point. Quality control is key though. You want to make a good impression. If you're unsure about a particular screen, get some feedback before adding it to your game's images.

That being said, I still think it's best to save some good stuff for in-game impact.

Ah, and don't let it get too monotonous. As in, don't post a lot of screens that are similar to one another.

Conceal but don't leave your audience in the dark as to what to expect. They look at the screenshots to help decide whether they want to play or not. You don't have to show the bits that spoil things, but you do want them to look at your screens and say "Oh, that looks interesting, let's play this!"

And that is more likely to occur if you have a varied group of images that appeal to all types of players - some game-play centric images, some dialogue/story/character centric ones, some mapping ones and a few that sum up what to expect in-game.

(Also makes it easier on submission staff to see whether your game is quality enough to approve when there's a few more thrown in.)

author=RedMask
Looks like most of you think I should add more so, I will add a few more some time soon.

author=GoatBoy
If you're unsure about a particular screen, get some feedback before adding it to your game's images.

I'll take your advice right now GoatBoy. Do you think I should add my title screen?
Here's a link
http://redgolimask.deviantart.com/art/Nsala-Liberation-Title-Art-453281083

This version of it doesn't show the New Game Continue or Shutdown but you get the point. The reason I worry is because I used a filter and I know some people don't like filters on images.

It's not bad, and custom art like that can be a good draw for potential players.

However, the background is really busy and distracting. The character art should be the focus of the screen, but she's very dark and low contrast compared to the rest.
So my advice - Simplify the background and add some contrast to the character.

If you decide not to edit it though (which I can understand since your game is already marked as complete and you may not want to bother adding a new download just for an updated title screen), I would still add it as a screen for the art.

Depends on how the game looks like? I usually want to see at least one screenshot of a "walk screen" and one of a "battle screen" to get an impression. But releasing new pictures gradually as LockeZ suggested is probably a pretty good idea to get some attention, especially because new screenshots will be on the front page. Requires the thumbnails to look so interesting that people click on them, though.

My only problem with too many screenshots is that all of your screenshots need to be awesome. If you're adding lots of screenshots, there's a good chance that you'll take a screenshot of something relatively mundane, and if I'm just browsing through games on rmn and click on a couple of screenshots from yours and don't see anything that grabs me, I might not stick around to browse the rest of them, which might have had something that really would have grabbed me.

The thing about our culture is that we've got thousands of people vying for our attention. If someone's looking for an rpg to play, they've got a lot of options, so you need to sell them on your game quickly. Each of your screenshots should provide intrigue into your game, hopefully in different ways as Addit suggested. Also, if you're showing off an aspect of your game--e.g. dialogue, graphics, hud, whatever--make sure that it looks GOOD. I can't tell you the number of times I've looked at a screenshot with horrible dialogue like some antihero talking about how badass he is or some jackass spouting a pathetic attempt at humor and said, "Not for me."

less is A-L-W-A-Y-S more... But this expression has never been about quantity, but rather, about quality. It's about figuring out what parts of a whole are important and why are they important. In the case of screenshots, their purpose is to give potential players a nice frame of reference of your game, and to entice them to actually play it or simply to follow its development. So, even if you have a thousand screenshots, as long as each and every one serves this objective, you're fine.

Many have said this, your screens have to be different, or perhaps even 'unique' to make the cut (Not that this is an enforced rule or anything). This is, I think, specially true for gameplay screenshots. Like the 'menu' example above, I often see people upload several battle screenshot: "This is the party fighting in a forest, This is the party fighting in a desert, This the main character casting fire 1, This is the main character casting fire 2, Good news, I just added a new skill to the game! This is the main character casting... fire 3" WHO CARES!? IT'S STILL THE EXACT SAME BATTLE SYSTEM,DAMMIT!!! *deep breath*
_
That being said, You should totally submit the title screen of your game. It's the first thing people will see. And you know what they say about first impressions; Think of it as a presentation card. Your logo alone can tell lots about your game... Speaking of first impressions, though, mine is kind of a mixed one. I like the custom art, but the background, besides being a filter, doesn't say "Africa" to me. Maybe you had something like this in mind? But it doesn't quite cut it.

Frankly, title screens deserve more love. They're not accepted as one of the three screenshots needed for game profiles because they're often the first thing that is made and it can be a sign of a game being too early in development. Plus many people settle for the default title screens that take no effort. But this is not always the case. =/

Whoops! This post came out kind of ranty... Oh, well...

Less is not more in this case. Just add what you think is sufficient, like showing the GUI, interfaces, a few battles, and if you have, screenshots with highly attractive graphics. But not too many of them. Just enough screenshots to entice players to download your game and play it to find out more. Too many, and it will likely kill the curiosity if not done right.