Monster Jump is the PlayBook's version of the popular game Doodle Jump. I'll be honest, I had no idea how to play this game and while it's pretty good in terms of functionality, smoothness and overall entertainment, it really lacks instructions for people, like me, that have never tried it.
Right now, the developer, TwoPinStudio, has lowered the price of Monster Jump from $1.99 to $0.99. Some of you thoughm, may see the lower price and at checkout have it revert back to $1.99. This should be resolved as the price gets changed through out App World soon.