Yeah thats probably the age of my PC. I get long load times between changing locations, also get that red/purple colour which is because of low graphic capabilities or something.
Despite highlighting this section, what I'm about to say applies to your other issues.
Your graphics card is the problem.
It's a pre-DX11 card, which is why you're getting those visual bugs. IIRC Unity stopped supporting below DX11 quite a while ago, and as a result so did The Twist.
My old/backup machine can run the game (not well, but an "ok" state at least) by using the "newer" card from my current setup - MSI R9 270 OC with 2GB DDR5 RAM.
The previous card in that machine could run it too, a MSI GTX 560 TI with 2GB DDR5 RAM, just not as well as the R9 270.
Getting your hands on something similar (assuming not a laptop) will give you a decent enough performance boost, but in the long run I do recommend saving up for a more modern system.