Oh wow, it's Adraius! Welcome back
Summary of major changes, hm... Well for the really big picture you'd have to see the
roadmap.
There's really nothing in a single location with a level of conciseness between that and the changelog itself, although one option could be to use the
Release History list to access the release notes for each version, since those tend to include a one-paragraph summary at the beginning, and lots more details (plus images) below that to demonstrate more about the given release. I'd say probably put aside a little chunk of time and flip through those as fast as you're comfortable with.
You can be sure there's been a simply massive amount of new features and content added since you last played. It's super fleshed out now, and I think you'll enjoy what it's become! Still more releases to go before good old 1.0 (and then some to come after that since I've promised at least one major expansion!), but it's been in a great state for a long while now.
Much of the old community we had here back in 2016 migrated over to the Discord channels, which is why you'll see less activity on the forums these days. There are a few regulars that still prefer the forums, but the community there is quite active by comparison... Honestly kinda sad since the years of great discussion aren't nearly as accessible there (or archived here for safe keeping and convenient searching), but realtime chat does have its advantages
