Man, idk wtf they did, but this game even on low setting has like a huge lag issue. Feels like I'm playing online cause I'm getting teleported everywhere, even the menu is bugged. Tried even using one of the boats and got stuck.
I 've encountered exactly the same issues. Huge delays (as if playing online with enormous ping) and 3 minutes long lag spikes with teleportation afterwards, invisible walls, freezing menus etc.
I was able to play the previous version just fine, but this one appeared to be almost unplayable on my PC, apparently due to the lack of video memory (I have a 1 GB video card).
I found out that 1 GB of hardware video memory was fully used, but the additional 8 GB of virtual memory was not utilized by the game at all. So, I blame it on sloppy programming.
I tested it on another PC with a faster CPU and a 6 GB video card. It went well.
The conclusion is obvious: the devs upgraded the game by screwing up the low-end system users.