This game's installation is bugged. At some point in time Nvidia changed the location where the PhysX dlls get put. This game's installation seems to only be checking the old location, not the new one. It "fixes" this problem by going and installing an OLDER version of PhysX. Which still won't work, because it's still probably in the wrong spot? There's a thread in the game's forum where some sharp users discuss a few fixes for the problem.
I don't really like either fix, because I'll have to remember to re-copy the DLLs from the new location into the game's own directory. If I get this problem with enough games (haven't yet) I may do what the video a user there shared and drop 'em into the System folder. That's never a great place to ♥♥♥♥ around, but it would get the files onto a path that any program anywhere will manage to find.
This is stuff we shouldn't need to do to make a game work. Even a game selling for $1. For a $10 game, that's almost beyond forgiving.