It's so sad when you go back to the early dev diaries on YouTube where the guys who made PA1 are clearly just creating a passion project. And now PDX has turned it into just another one of their DLC treadmill games and introduced a slew of game breaking bugs in the process.
PA is still fun if you can look past the bugs. It's a really interesting twist on the colony sim formula to have basically an adversarial relationship with your pawns. It makes you think about security zones in much the same way as someone designing a secure facility like a bank vault or military base.
I believe the last pre-Paradox build is still available under Steam Betas.
It's a damn shame what Paradox did to the game. It turned from a near-perfect sim with excellent optimization and stability into a laggy, buggy mess with loads of DLCs that both fixed and introduced more bugs. So the usual Paradox product, where stability is completely random based on which DLCs you own.
First game was relatively bug free before paradox bought it. Then once they started pushing them to add DLC content, the bugs started appearing rapidly. It's so transparent exactly what was happening behind the scenes. PDX pushed them to add DLC to recoup their investment, and the deadlines they pushed didn't let the studio implement them properly on top of the existing codebase (which they didn't create with endless DLC in mind) without cutting corners like crazy.