As promised, here's a brief tutorial on creating games using Classtools. Well, actually, not quite ;-P. I just remembered that Teacher Tube has a video tutorial, and it may well save me the effort. I'll embed it here, and if you still have problems, just post a comment and I'll try to help.
One thing worth mentioning, however, is that Classtools host the games in their own server. You cannot download your creation and host them yourself. Whether you use the embed option or the html file, it leads you back to the game in their server.
I've used their games quite a bit. Here are 2 examples:
Index of all material by category
How to create Content Generator games
How to embed or link games in your website
How to force links to open in a new window
How to take a screen shot