StencylWorks is a great game-making program if you are not able to code a game itself, it outputs the game as .swf so you can upload it on the webs and play in browser and share with other people more easily. Personally, I had a few problems with Stency, but still it's probably the best think I have for now, since I don't have enough time to learn a complete programming language. At first, there'll be a few things to learn so you can master stencyl, but the results will be pretty perfect in the end. It's totally free (unless you go pro, but it isn't really different), cross-platformer and easy and I'd suggest giving it a try.
Well, there is another way, Construct2, but I can't get used to it personally.