i know this sounds a bit stupid but, has anyone tried this?.

an MMO where players start in a pseudo medieval age, then as history progresses, devs keep putting technological developments, things like the discovery of gun powder allow for the use of cannons and muskeets in combat, then later, steam engines allow for the creation of mechanical vehicles, including tanks, steam powered barges and airships. and later achieveing space travel, first to another planet in the same solar system, then the next star system, and later, to the whle galaxy?

i know i know its a crazy idea, but to be honest, it would be interesting. the only issue i find is the gamelpay changes, the shift from swords to guns its a big step, magic keeps the same and could evolve with the time, but players who like to melee would have to change to ranged combat.

it would be a really long process also cause you have to think:

1. resources (from wood and stones to high tech allowys)

2. crafting (the crafting "curve" would be like playing EVE in terms of learning)

3. combat(again, from the uggah buggah with obsidian spears and wooden little canoes, to holy sh*t laser sables and capital spaceships)

4. transport (from land, to sea, to atmosphere, to spaaaaaaaaaaaaaaaaaaaaaaaaaace)

5. clothing(both armor and vanity clothing, how do style works in a simulated environment?)

6. cities and constructions (changing architecture and the rise and fall of empires)

Pretending for a moment that someone had the resources to do this as an MMO, I still doubt it would work out well.

The problem is that the concept calls for major shifts, the sort of shifts that turn winners into losers quickly.  I'm talking a case where Monday I'm death incarnate on the battlefield seemingly impervious in my magically imbued armor, Tuesday gun powder is discovered, and by Friday everything I had worked on obtaining previously is just an ornament in my home.  In a matter of days you have completely made obsolete my gear, skills and likely the charcters attributes.  The factions are likely to shift at about the same time too.  It's safe to say you will piss a lot of people off at that point.

The other issue is precognition.  Am I willing to fight for "worthless" land in the age of wood?  Oh wait it has coal which replaces wood as the primary fuel, yup I'll fight for it.  That sort of conflict between the in game now and later will create an odd atmosphere, one where people will be positioning centuries out.

Finally, I doubt it is possible to tune the timing of technology introductions in a way to satisfy a player base.  It will always be either too fast or too slow.  I might love the game in one period (say the early age of gun powder), but hate the game after cartridges appear (just an example).  So I'd want that time to last as long as possible, while Joe OTOH is impatiently waiting for the moonshot before he will sub.  That isn't even considering the "work" put in to building the toon, positioning or whatever else.

Don't get me wrong, it could be good in other genres (TBS/RTS) or as the backdrop of some quirky story (sword art online or .hack).  The only other option I can see is to start or end around gun powder.