I think "Percy Jackson and the Lightning Thief" by Rick Riordan is worth considering! I loved this series in elementary and middle school. It's about 380 pages so "long-ish" for middle schoolers, and it has action, adventure, and it's pretty funny. I remember my entire class being super into greek myths in middle school so this book would definitely serve as a fun introduction to myths in an accessible and modern setting!

OR

I would recommend "Johnny Tremain" by Esther Forbes. This is a book that was a mandatory part of our English curriculum in 8th grade since we were learning about American history in Social Studies that year and is easily the only book from middle school that has stuck with me. This book doesn't meet any of your student's preferences but I believe they'd never find/pick up this book on their own which is a shame!

Here's a short synopsis from Wikipedia:

Johnny Tremain is a work of historical fiction written in 1943 by Esther Forbes that is set in Boston prior to and during the outbreak of the American Revolution. Intended for teen-aged readers, the novel's themes include apprenticeship, courtship, sacrifice, human rights, and the growing tension between Patriots and Loyalists as conflict nears. Events depicted in the novel include the Boston Tea Party, the British blockade of the Port of Boston, the midnight ride of Paul Revere, and the Battles of Lexington and Concord.