The game froze constantly on multiple starts, a lot of times it would freeze in the load screen but a couple of times I got to the menu, however it would freeze when trying to start playing. I was able to get into the settings menu and switch off vsync and that appears to have fixed the issue. Based on other people's reports this may be a NVIDIA specific issue. After this the game appears to be working. It's a bit slow but that's probably more to do with my system specs than anything else.

I tried various other protons as suggested but that didn't make any difference (if anything they were worse - freezing before reaching the menu)