The changelog has a full accounting of changes (read between builds 363 and 408).
Anyone having trouble with their download – please see this forum thread.
For mods, you may want to start with the Big Bang Alpha 3 mod pack.
The big new thing is the faction system. Now we have generated factions like pirate bands, outlander towns, and tribes. They even generate names for themselves! This leads to hilarity with three-way battles, buying off factions to get their allegiance so they’ll send fighters to help you, and getting raided by a dude’s friends after you capture him and beat him up. The video shows this in detail.
Alistair Lindsay’s music is in this build! Al is obviously still refining and expanding the music, but I think this is a great start. Listen to the dulcet tones of the mixed sci-fi/Western theme he’s been cooking up for the past 3 months.
There’s now a planning tool, so you can put down inert designations that don’t do anything. This helps you plan your colony visually, on the map. (I recommend you don’t put thousands of them, though; they’re not rendered in a super-efficient way right now.)
The map generates in a more varied way now, using a data-driven algorithm which you can mod (from the MapGeneratorDefs folder).
Tons more stuff is moddable now. And you can write proper code mods that link DLLs into the game, easily, and in a way that’s compatible with other code mods.
There is a proper hunting system which allows you to mark animals for hunting and let your colonists handle the details. Beware sending unarmed colonists to hunt boomrats by kicking them to death. The rats go boom.
The game has partial support for localization now. This was a last-minute addition, so it’s not all locked in yet and not everything can be translated. But lots of stuff can be. Now the Russian hackers can stop hacking the DLL to make the game display in Cyrillic. A rough German fan translation from TheEisbaer is included with Alpha 3.
The bill interface has been redesigned and smartened. You can now set colonists to maintain a certain stockpile of a certain kind of item. No more repeatedly ordering them to cook 4 meals every day. Just set it to “make until you have 10 meals” and it’ll run forever.
Finally, and very important, is the many small AI improvements. The AI in Alpha 2 was a little bit derpy. This was a consequence of the game increasing in complexity but the AI not becoming smarter fast enough to handle the new situations it was trying to deal with. Now, you won’t see colonists eat raw potatoes out of the stockpile when there is a dispenser ready. They will put food in the dispenser, then use it. And colonists who make something at a table will actually put it in storage now. And there are many other improvements.
Have fun! See you on the forums, Twitter, and reddit: