I've seen this question a few times... usually when the denizens of this site reach level 20, and stay there for a while. "Why does this level take so long?!?" they cry. "It takes forever to get away!"

Well, being a long-time RPG player, I actually know what an MS is. It may go a long way towards explaining why the level lingers for well-nigh eternity (or, at least a month):

Enyx Software released several RPGs for the NES in the early 90's called "Dragon Warrior." DW1 was considered one of the better RPGs at the time of its release, until it was dethroned by Final Fantasy. Each new release added more features, and more interesting ways to do battle (slot machines, decks of cards, etc.), culminating in it's final NES release, Dragon Warrior 4 (one of my all-time favorite RPGs).

DW4 contained 3 mini-campaigns (to introduce the major characters in the story) and one major campaign. It was the typical Japanese RPG-storyline (find obscure items in dungeons while fighting off monsters and the Boss; bring them to The Ultimate Center Of Evil TM to defeat The Ultimate Evil TM. To my knowledge, it was the first RPG that allowed you a larger campaigning party than you could fit in your combat party (they travelled in a covered wagon beside your party), allowing you to "tag-team" in and out as the situation dictated.

One of the more interesting critters in the game was the Metal Slime. In one part of the main campaign, you were near a town on the edge of a desert. If you were feeling so-so about your party's level, you could activate a Monster Lure near this town, and be jumped by single Metal Slimes. They never hit back, so the danger to you was minimal, but they were very hard to hit (a full strength hit might scratch it for 1 damage... 2 if you were lucky). They had 4 HP apiece, so they died pretty easily... but, again, you had to hit them first. The prize was a measly 5 gold... and 1350 xp, which, at that point in the game, could mean a solid level up.

I recently tried to play the game over again, but it looks so dated compared to today's newer graphics and games that I sort of gave up an hour into it. Still, I did beat it the first time I played, and had an enormous amount of fun doing it.

So I'm sort of excited about being a Metal Slime nowadays... and, to be truthful, it sounds a lot better than Gitaroo Man (whatever that is).