To simply introduce, Project Spark is developed by team dakota and skybox labs.It is published by Microsoft Studios.It is a game maker "Where Players Create and Creators Play". The website quotes project spark
"As a powerful, yet simple way to build and play your own worlds, stories and games. Experience the ultimate interactive playground, delivered as a free digital download with many options for enhancing your creative experience."My definition -Its a playground where you can create your own Story --> World --> Game. To shorten A GameGround.
Building a game is not an easy task as it involves many stages which includes design,art,mechanics,development etc.Building a game for Xbox is much more difficult as the game art is the most strenuous part to crack.This platform gives you all the required content to built your game world.
If you are aware of canvas in HTML5, Project spark is also a digital canvas which can be used to make games,movies and other experiences.A player can download other user-generated content, remix that content or create content of their own. A player can use the Xbox controller, keyboard and mouse, touch-devices, Kinect and SmartGlass to build experiences. Kinect can be used to animate models and record audio. The created environments can contain mountains, rivers, and towns. The player can also create events, like inter-character battles. Created items and objects are able to be shared with other players.
Players choose whether to start from a blank map or a pre-designed level, but always have the tools to customize the topography, add plant and animal life, and program behaviors for specific objects, such as a rock that bounces when a player is nearby.The topography is modified by pushing and pulling the earth, digging through surfaces after changing the view to adjust a wall or create holes in it. Anything added to the terrain reacts to the circumstance, such as grass covering the floor and the vertical surfaces becoming rocks.
You can create a game for Microsoft windows 8.1 and Xbox.
Here's what Jason has to say about Project Spark,[Jump to 2:11 for the interview]
Creating Games with Project Spark [Course on Microsoft Virtual Academy]