Fact is that art is an important part of visual novels. Obviously, good art will make it much more enjoyable. However, it's all about balance. So if your art is unusual, people will generally enjoy it anyway if the writing is good enough to draw the reader in despite the art.
Other than that, chibis are perfectly fine. Of course, it also depend on what kind of visual novel you want to do. The story has to fit the art style somehow. So if you only use chibis, a hentai game or an otome where you talk about rippling muscles and whatnot probably won't work. Long story short, if the story is about as cute as your chibi art, go for it. And if it's not...go for it anyway. Or get yourself an artist.
Whatever, just do the best you can. People here will appreciate it, because they can see that you put your heart in it.

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Le DeviantArt page:
http://chilly-chan.deviantart.com/ (I don't really upload a lot...even though my PCs full of unfinished drawings..>.<)