The only program out there that you can use to make a real high-quality flash game that is free is FlashDevelop, but to use it you are going to have to learn ActionScript 2 or 3, which takes a considerable amount of time.
Actually, there are a few more free tools to develop flash content. The Eclipse IDE is free and there's an ActionScript plugin for it on SourceForge somewhere. You can also use the Flex SDK.