The Textfire Demo 12-pack was released on April Fool's in 1998, claiming to be demos of an upcoming commercial studio called Textfire.
This game (one of the many from which Adam Cadre scrubbed his name) is based on Flowers for Algernon. It has extensive styling of the standard parser errors, written in the voice of someone with bad spelling and grammar.
A lot of work went into this joke game, and it's an interesting concept.