Pixel Maker is now available on Steam in early access form. Here is the description of Pixel GameMaker MV:
Create action games with ease - no programming necessary
Create endless fun with “Multi-Viewpoint/Multi-Versus”
Allows for both top- and side-based views, as well as cooperative or competitive local play between up to four players. Works with any genre, so the games you can create are limited only by your imagination!
A simple way to create rich and beautiful game graphics
Using the graphic import feature, physics engine, particle effects, and multiple layer combination, you can create your own ideal game in exactly the way you want to make it, easily and without all the hassle.
If you are interested in learning more, I purchased the engine and did a brief hands-on, mostly walking through the interface. That video is available here as well as embedded below. The early access release is currently available at %20 off the retail price, currently just over $60USD. As you will see from the video below, this is an early access product and some features are certainly missing, incomplete localization certainly topping the list!