There (in the link I shared) is also a step-by-step 'How to' which I think will work even on the current Proton version.

It requires to have install vc1decoder, which will allow playing all the videos. It looks like it crashes because of the intro video. Playing with a keyboard and mouse isn't supported. Notice: Deadly Premonition 2: A Blessing in Disguise requires a controller in order to play. I deleted all the local files after each change of the Proton - to be sure that everything is set up from scratch). Deadly Premonition 2: A Blessing in Disguise is an open-world survival horror video game serving as both a sequel and prequel to the original Deadly Premonition: The Director’s Cut. Also, you can activate developers mode in which you can delete all local files of the game that were created after the first run (e.g. If you change it to some version you don't have installed, it will automatically download and use :). So yesterday I tried Proton Experimental as well as some older Proton and it does not help - btw now you can manage Proton core straight from SteamOS UI, you can just select a game and in its properties change the Proton.

Steam deadly premonition 2 download