Nothing like good ol' Dwarf Fortress, the indie game you can count on to be developed full-time. Thanks in part to Tarn Adams' development log, we can keep up with all the new additions and bugfixes to this incredible games. And
since 39f, there's been quite a few. 40c's big addition over 39f is embark stocking profiles, enabling you to build a profile that you can use with each expedition, saving you the hassle of redoing your items and skills every time to restart. There's also a plethora of bugfixes, from fixing display errors to mood lockups. You can check out the full list of changes between versions on
Tarn Adams' devlog, and can
download the game on Bay 12.