On the monster hill it's crawling with coloured monsters: red, purple, green, just name it. It's your job to make them all disappear in this Bejeweled-like game. Let the monsters swap plases so you get one or more groups of at least four identical monsters. These will disappear. The don't have to line up: as long as the little monsters are next to eachother, they form a group.
Hold the left mouse button and move over the monsters that you want to switch places.