Those two should be enough.
Looks like Valve is giving everyone everything they need to keep Greenlight populated and creating more hats for the hat god.
I say snarkily as I download the free version of Gamemaker and wonder how much better my life would be with a graphics tablet.
I like the idea of people making games in GameMaker, and uploading it to the workshop, is kind of similar to modding, and I like modding.
Does the GameMaker has an achievement of making a game?