You could do a Bingo type of game, but that would take little effort and probably wouldn't teach much. How about a Memory/Concentration game, with questions matching answers. For instance, in Memory, you'd turn over a card that shows an apple. You turn over a second card, and if it's an apple, you take the cards and to again. With Animal Farm, if the first card you turn over is a question, then the second card needs to be the answer to that question and vice versa. Hope that makes sense. These cards could also be used as flash cards.
I agree it sounds like fun. Personally one of my favorite games is Cranium and it's pretty good for this because it can appeal to every type of learning style. You have your Creative Cat, where students can sketch or sculpt scenes, characters, or significant items from the book. The cool thing is that some of these are done without looking at what you're drawing! There is Data Head where you can ask multiple choice questions and True False questions. There is Word Worm where you can focus on vocabulary and key terms in the book. Finally there is Star Performer where a person acts out certain things, pretends to be characters, hums songs, etc. It would be really interesting and there's really something for everyone. If you don't know the game you should check it out because it would be unusual and if you are a teacher the students can really get in to creating the prompt cards for each category, perhaps a big group assignment, each group creates a category.
It could be a LIFE-like game where the players move along toward the winner's spot (all-time ruler?) while landing on "hostile take over, move back 5 spaces" or "successful coup, move ahead 3 spaces" blocks and others you can think of. If you are a student, ask friends who have also read the book for additional ideas. If you are a teacher, consider allowing your students to help brainstorm ideas for the DRAW pile of cards or blocks along the brick road that games pieces must cross over to get to the end. Good Luck! Sounds fun.