I finished teaching the third round of my mini-course on Friday, and was so exhausted (in a good way) that I accidentally fell asleep at 9pm.
This year, I tried Scratch as a platform for making our game projects instead of Game Maker. One of the biggest factors in this decision was the community on the Scratch website; I figured the girls would be more likely to continue playing around with Scratch because of it. Game Maker users seem to have minimal sharing of projects in comparison.
On the first day in the lab, I had the girls look at the Getting Started Guide from the Scratch website. Then I got them to go through a few tutorials on Shall We Learn: Sprite Interaction via Variables, Working with the Stage, and The Pong Game. I provided a few links to useful resources like the Scratch forums and reference guide, but I'm not sure anyone looked at those.
As I walked around watching them try the tutorials, I noticed how quickly they were willing to start exploring on their own. Many were already drawing their own graphics and playing with the many code blocks available to them. I could be remembering wrong, but I don't recall that sort of confidence with Game Maker.
As the week progressed, I was really impressed with what I was seeing. However, there were a few snags that we hit with Scratch that would not have been a problem with Game Maker. For example, one group wanted to make a side scrolling game, which requires a lot of extra work and thinking with Scratch. Another girl wanted to be able to shoot bullets from a plane, but Scratch's sprites don't appear to be objects, but rather tied more precisely to instances. In other words, you can't have more than one instance of a sprite.
At the end of the week, I got the girls to complete survey, which included questions about how much they liked Scratch. Some seemed to think it was a great choice, others... not so much. I'd guess that those who were more limited in what they were trying to accomplish probably didn't love their Scratch experience. Some even suggested using Game Maker again next year.
Assuming I am able to do the course again next year, I have not yet decided which software I will use. Both have their pros and cons. I may wait and see how using Scratch for my upcoming introduction to computers class for arts/social science students goes first before figuring it out.
You can see the mini-course material and some of the games that were made this week (many of which are not yet totally done) on the web page I gave the girls to look at throughout the week.