Its likely due to one of the assets being missing. I'd recommend reinstalling. Please get back to me if the issue occurs again and I will look into it further, thanks!
Ok, so it might be due to the bosses, the game functioned fine until what I presume, the boss cards appear. The errors this time, yes multiple, are the following.
Traceback (most recent call last):
File "!REPRIEVE.py", line 6546, in <module>
File "pygame\sprite.py", line 556, in update
File "!REPRIEVE.py", line 2162, in update
File "!REPRIEVE.py", line 2091, in trigger
File "!REPRIEVE.py", line 5608, in addEnemyCards
UnboundLocalError: cannot access local variable 'bossCards' where it is not associated with a value