For those that haven't been keeping up with the playtest here's a summary for most of the updates so far. I'll also be ending the playtest pretty soon and will be putting up a demo instead. If you've been playing the playtest you won't notice much difference between the two though.
Additions
Added save/load/import/export functionality for custom units.
Added 71 new units and 2 new factions.
Added victory conditions.
Added 25 passive skills.
Added basic town management options (simple tax system, migration/merging, deconstruct button)
Added faction personalities. Factions will behave differently in terms of diplomacy based on their personality.
Updated the character sprites of 9 units.
Performance optimizations.
Added window mode and resolution options.
Changes
Made improvements to the research and garrison UI.
Made improvements to the experience/leveling system.
Quality of life improvements (better camera following, hold position, multi-select workers)
Expanded squad system (10 > 20 squads) with improved UI and clickable map icons.
Made improvements to diplomacy and the faction AI.
100+ bug fixes.