In order to get the game to look sharp you have to turn up the Resolution Scale to the maximum, which costs a lot in terms of performance.

Alternatively you can set the Resolution Scale to half (game runs smooth but blurry), then open the following file with Notepad:

C:\Users\Username\AppData\Local\Impact\Saved\Config\Windows\Engine.ini

And add the following lines at the end of the file:

[ConsoleVariables]
r.Tonemapper.Sharpen=4

You can choose a different value.
While the texts are still blurry, the game itself looks fantastic without any performance cost.

Hope it works for you.