

If the adverts are completely optional, this is the best way to do it. “Here, if you watch this ad we’ll give you free shit!” is way more likely to get me to watch whatever it is, but “You will watch this ad or you won’t get to play anymore” is the fastest way to get me to uninstall.
In situations like this, the answer isn’t to argue over the interpretation of the words: it’s to fix the words.
If the writers intended “no excessive capitalization or excessive grammatical errors”, then it should be changed to that.
If the writers intended “no excessive capitalization and no grammatical errors”, then it should be changed to that.
Both situations remove the ambiguity and prevent pedantic internet arguments about language interpretation.