Navigate to %localappdata%\SugarShack\Saved\Config\Windows\Engine.ini

To disable all of the effects, put at the bottom of the engine.ini file linked above:

In order, these disable the following:
Lines 1-3 : motion blur
Line 4: Temporal Anti Aliasing
Line 5: Film Grain
Line 6: Depth of Field
Line 7: Lens Flares
Line 8: Chromatic Abberation (Rainbow effect around edges)

You can play around and test which settings you want to disable but the Motion blur and Depth of fields are highly recommended as they are the effects making the screen all blurry and they are the settings the most likely to make you feel sick quickly.

This guide is heavily inspired by the one made by Druark right here.
I could simply put a link to his guide and not write anything else at all here but I was afraid that someday, his guide get deleted for whatever reason so I wanted to make sure this information remains accessible because Sugar Shack without modifying the files is really painful to play.
Go to the guide of Druark and thank him very much for spreadind this great information about manually tweaking UE4 and UE5.