Thoughts:

Stories should have a single climax...possibly two. Certainly no more than three. Five? Right out.

I like villains with back stories. Giving the Joker no back story made him extra specially creepy for a time, then eventually just made him annoying.

Where does the Joker find time to continually be planting bombs everywhere? On the same note, where does he find time to keep renewing his makeup? And still plant bombs? And hire new flunkies (since he keeps killing them off)? Has he been reading "The Seven Habits of Highly Successful Creepazoid Supervillains?" This guy could give lessons to an efficiency expert.

No matter how badass (batass?) Batman gets, no matter how many cool fight moves and nifty technological doodads he has...I simply can't take the little pointy ears seriously.