Play games like Halfway house, Esteria, My New Memories, Price of Power or Eternum and you will see what good English really is.
For Dark Magic the first half is okay but after that the text quality becomes more bad with every scene. Anyone can objectively sees that.
And no, as you can see it's not my second visual novel, I've done enough, independent ones like dark magic and more professional ones like those you can find on Mangagamer.
But hey, if you enjoy that level of English and it doesn't break your immersion good for you. Personally I prefer to play better quality games, that's all.