Does Space Age Let Me Continue Vanilla

[Rephath]

I just beat the game (again) and I'm not looking to start a new one this soon. If I buy Space Age DLC and boot it up, do I have to start a new file to play Space Age content, or can I go straight to space from my current save?

[Nonotorious]

You can go straight to space but i'm unsure on the world gen in regards to the other planets. The devs recommendation is to start a new file, maybe i should load up an old map and see if it breaks.

[Fel]

You can technically use an existing save, but you will have to rework some of your factory in the process and you will lose access to some things you already had due to the changes in the tech tree.

Note that just like with normal mods, it is usually better to start fresh.

[Chindraba]

If you do load your finished game in space age it will give you the option to "Fix and load" and just "Load". Fix and load will "fix" the save by removing the techs you've unlocked which are now behind planet sciences, such as level 3 modules, artillery, cliff explosives and spidertron. It will also delete any of those things in inventory and on the map. The machines making those things will still be there, but they will have the red "NO" circle/slash logo on top. The goal here is to make the game as much like it would be if you had played it from the start rather than loading a completed game.
If you really want to continue as if nothing had happened, the "Load" option will make as few changes as possible. The satellite will be removed as it is not in SA at all. Most of your stuff will still be there and most of it will still work. Exactly what will be removed is unsure.