As for the flash games, I would like to recommend content generator which you can download to generate quiz. http://www.contentgenerator.net/forum/index.php?&CODE=01 Just register as a member for free and you can download some of the software for free. Of course you can also make use of the tools available in the asknlearn portal to create the swf file. The quiz will be generated in the html and swf(flash) format. The graphic is good and the 'Fling the teacher' Quiz is quite humorous.
I generated a quiz on river studies for the sec 1 using the 'fling the teacher' software here - http://lily_lee68.webs.com/River.swf
There are other free software such as a simple multiple choice generator, half-a-minute, space invador, match-up etc. Some more examples which I had created below:
http://lily_lee68.webs.com/basicHalfamin.swf - the students have to guess the economic terms based on clues given.
http://lily_lee68.webs.com/economicindicators.swf - a match-up game on economic indicators
