Stardew Valley - A Look Back

ConcernedApe has taken a look back at development on his blog showing some early work-in-progress screenshots. Also the PC will be getting multiplayer first according to this tweet from ConcernedApe in response to this PCGamer article.

Also, the game was called "Sprout Valley" at this point:

As you can see, the "bones" of Stardew Valley were pretty much there way back in 2012. So why did it take 4 more years to complete?

Well, you could say I was "polishing" the game during those 4 years.

I ended up re-doing nearly all the art several times. I redid the vast majority of the soundtrack. I expanded the NPC's way beyond anything you'd see in the 2012 version. I made the map way bigger and more detailed. I added JojaMart and the Community Center. I added tons of items. I totally changed the crafting system and the mines.

In fact, at one point, the mines were going to be procedurally generated and fully destructible, with lakes you could cross by raft:

[...]

Eric Barone released Stardew Valley as a singleplayer game, but only because multiplayer support wasn't finished yet. So we've known for a while that multiplayer is coming to Stardew Valley-officially, that is-and today it's been revealed that the big patch may be coming this summer. But we're not completely sure yet.

Nintendo announced today that the Switch will be the "first console" to have Stardew Valley multiplayer when it releases for the system this summer. As "first" is qualified with "console," the multiplayer update could come to PC at the same time, or even earlier-though nothing about it has been announced explicitly.