Did anyone else place this like a year or two ago and coming back to it discover that it is completely unplayable like I did?

I remember this game running smooth as could be and I just left settings maxed out. I just turned it on again today, left things at default, and the game is running at like 20fps and lower, often frame dropping so hard I can't even jump up a hill properly.

I'm on a slightly older machine, but it DID run this game beautifully and now it chugs so hard. I took the time to check my settings, update my drivers, try some steam launch params, and play with the graphics settings but I couldn't get it to stabilize, verify integrity of game files. The best I could do was make it look like crap and have decent fps - but still had the sinkhole level frame rate drops.

This is nuts, seriously, ECO - you've broken your game.

Update: Still playing with settings, no luck - advice welcome of course.