Stencyl lets you create games without knowing any code. It has a drag and drop interface, and you can edit your code if you know how.

The drag-and-drop gameplay designer features a simple block-snapping interface with new functionality and hundreds of ready-to-use blocks.

Advanced users don't need to shy away from Stencyl as they can create and share their blocks, extend the engine through code, import libraries and write their custom classes that interact seamlessly with block-based behaviors.

Photoshop users will be comfortable in the Scene Designer. It has similar features including a selection tool, zooming, grid-snapping and flood fill to help you quickly craft complex worlds out of actors, tiles, and terrain.