Quest for the Parts of Speech is a fun quest based game. This game does provide instructions and examples of what the different parts of speech are. When players succeed, they also feel a sense of accomplishment, as they help the king vanquish the villains.
Disclaimer: this game requires strong reading skills, or an adult to help read the text. My daughter did really good, at age 8, with correctly identifying nouns, verbs, and adverbs, but she needed a lot of help with reading the passages.