2D artist for Game Dev book

I'm currently 70% through writing a book on HTML5 Game Development that is set to be published mid-year. I'm making the art assets for the examples myself, but they are pretty programmer-art-y. The publisher is happy with my dodgy drawing skills (and don't want to hire an external artist) but I'd love for the games to look great. So... my offer is... "exposure".

[EDIT: thinking about this, I don't mind doing some "self-funding" if it makes the book better: if "exposure" is just not enough then also let me know a price range]

The book will be released in print and digital versions. I have had a few other web-related books published in the past that have done well (and even been translated into several languages).

I'm very happy with the technical contents of the book and I think it will be well received. You'd get credits in the book, and I'm the writer so could also drop some links/shout-outs into the story line that weaves throughout the chapters. The publisher will also be showcasing the games in a marketing push.

There is not a huge amount of art required: roughly 3 very (very) small games worth. The book is "from scratch" so the games are quite simple: a shoot'em up; a grid-based 80s dig-dug-esque; a platformer... That's why I'd like the art to add some depth - with a weird, quirky, or eye-catching style. The style would be aesthetically similar across all the examples, and assets could be reused where necessary.

So if you have an interesting/weird/nice style and would like to see your work in print, then let me know!