This game cannot be completed because your aiming is restricted to a small box at the centre of the screen. You can get right to the end boss without this, but the final blow can't be delivered without being able to shoot down. I am running Windows XP with 8600 GT, and the latest dpfix on a 16x10 monitor (1440x900). I've tried the following: windows 98 and 95 compatibility modes and alt-tabbing, as suggested on one of the steam forums. I got it in the sale last week at a very low price, so it could be worse. I've had to watch someone else complete the game on youtube. Very annoying. If anyone finds a fix - please post it here!

Actually it is possible to win this fight, even in the terrible ported, auto aim infested PC-Version:

http://www.gog.com/forum/deadly_premonition_directors_cut/aiming_problem_boss_fight_chapter_25_last_stage

Hello to all who has a problem with the aiming:

During my play I extendedly tabbed to my desktop, after I returning back again, this small aiming box was gone. I could shoot in all directions without a Problem and beat the Boss :D

I really enjoyed the game!

Is this due to mouse controls or what? I played through with a controller and never had an issue with the aiming. Plenty of other problems though.

I'm not sure... I played with mouse and keyboard and never encountered this issue. Like you said, I came across a few others, even though I found them to be more annoying than game-breaking.

I'd still highly recommend Deadly Premonition; it's niche, there's no denying it, but in this day and age I blame it on the gamers for not doing a bit of research before buying a title. Whether you're a fan of quirky horror japanese games or a long time Twin Peaks aficionado, you can't go wrong with Deadly Premonition.

[EDIT] typos. Hooray!