Isn't it useful for a dev to know that some people (potential patrons!) aren't playing his game because of the poor english? That way, he has a chance to do something about it if he wants to.
It's probably not that hard to find someone to look over a few hundred lines of text and propose grammar fixes etc.
I must say, I'm not a native English speaker, but I do like to have my writings as good as possible and I'm not developing a game that others may pay for it. There are several free tools to help to have a better English text, I use grammarly for my WhatsApp (web) and email messages, the free version does this job very good.
I like to read things with good grammar and with no errors in my own language, so I expect others to like things well written in their own language, the fact that it's a game does not prevent it from been well written, IMHO, if you are going to do something, try to do it as best as you can...
This is just an example of grammarly correcting errors: