Amnesia & Penumbra Series Mac Issues

[atomicenergy]

Hi buddies!
I'm writing this to know if there's any way to fix the issue i've been having with my Amnesia and Penumbra Series Games.

When i first bought them, it was in the week there was like 70%+ discount on almost every game on Steam, so it was perfect, instead of paying 40 bucks for these 4 games it costs me 9$. I was happy! The first weeks were pretty fine, i mean the games were running ok but after a little bit of time the following happen:

- Multiple lags with nonsense reasons
- When moveable objects hit each others (against walls too) there's a remarkable drop on the framerate, really laggy.
- In the videos of Penumbra on Youtube the monsters were patrolling around, but when i play in Black Plague the monsters stand still until you make noise.
- Whatsoever it totally ruins the experience of playing a game.

Is there a way to fix this or maybe is it my computer? I think it couldn't be my Mac because it is actually really powerful, one of the most recent ones.

Any suggestions? Thanks!