Titan Quest Series I've Finished
It's just one game with forth expansion, but the age of this franchise from 2006, and kept going, even in 2021 they release another chapter of the game (hope not the last) surprisingly with the same PathEngine! And I really wonder, how many chapters been cut from game, and now they start releasing it, perhaps there's still more act unopen!!!
2007-2008 Titan Quest complete campaign ~1x "Lost save files"
2020 Titan Quest: Anniversary Edition complete campaign 1x*
2020 Titan Quest: Immortal Throne, complete campaign 1x
2020 Titan Quest Ragnarok, complete campaign 1x
2020 Titan Quest: Atlantis, complete campaign 1x
2021 Titan Quest: Eternal Embers, complete 1x*