Comparing XNA and Silverlight for 2D game development

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/comparing_xna_and_silverlight_for_2d_game_development.htm]

Most developers are interested in writing games, if even just as hobbyists. That's why there's all this buzz around about two (relatively) new technologies - XNA and Silverlight. I wrote a simple real-time strategy on each platform, and I found the differences very educational. There's a lot of overlap. For example, the powerful Farseer Physics Engine is being marketed to both groups. The best blog I've seen so far on this has been MVP Bill Reiss's stuff - he's written good tutorials for game development on both platforms.

 

	XNA	Silverlight 1.1
Summary	A platform designed explicitly for gamer development. XNA is obviously more powerful, as it's a client download, requires DirectX, and is optimized specifically for games and high-speed (including 3D) rendering.	A new plug-in that hosts xaml, letting you write thick-client applications in the browser. Silverlight lets you write many things, of which games are just one.
Why care?	Solves rendering and gameLooping such that anyone can now make a simple game.	Allows you to write simple games over the web, so you can share with anyone.
Age of technology?	Came out about a year ago	Still in alpha
Rendering	The Game class has a built-in gameLoop, which fires both an Update and Draw. The Update method updates your models, positions, and logic, whole the Draw method then uses those models to draw images to the screen via the SpriteBatch. If you want to add a new object, simply display its sprite. If you want to remove that object, stop rendering its sprite. For 2D games, XNA just displays sprites - it's not vector based (as far as I could tell).	You add objects using Xaml, and then the objects stay rendered until you explicitly remove them from the root canvas. Xaml is vector based, so you can draw shapes as well as sprites.
Animation	Developer manually handles by updating the position and what images to show in the code.	You can use Xaml storyboards for simple animation sequences. You can also set the position, rotate, and clip of a sprite. SEE: how to make an animating sprite
Transparent Images	Handled by setting all pixels to magenta	Handled by making a transparent png image.
Killer Features	Awesome performance 3D games	Deploys over the web, on all major browsers, using just FTP (you don't even need ASP.Net on the server) Integrates with Html and Ajax, so you can also use web controls (for example, TruckWars uses an html dropdown to let you select levels, and an html button to both reset levels, and provide a confirm box)
Big Problem	Deployment is bad (you need to download 3 separate packages) Lack of basic controls - like buttons and dropdowns.	Slow performance compared to XNA, but good enough for classic 2D games.
Benefit to learning	Good way for a hobbyist to get started.	I personally think that the skills needed to make Silverlight games are much more marketable because they can also be applied to enterprise and business development. For example, if you can make Pacman in Silverlight, you can make graphs and input controls that the business world cares about. While XNA can make graphs too, there's a much bigger market for web development than on the XNA platform.
Tutorial	Bill Reiss on XNA	Bill Reiss on Silverlight
TruckWars sample	TruckWars in XNA (you need to download a bunch of stuff)	TruckWars in Silverlight (runs right in the browser)

 

Silverlight and XNA are both easy to get started, especially with the active communities evolving around each of them. Even if you're a full-time .Net developer, it's still fun to toy around with these technologies on the side.

 

Personally, I started with XNA, but quickly moved to Silverlight. For me, the deciding factor is that (1) The Silverlight skill set is more applicable to my job (enterprise development), (2) Silverlight is so much easier to deploy, so I can share the results with others.