Gravitron Ultra XNA is a multiplayer space shooter game developed in less than 3 months by 3 people using the XNA framework. It won awards for best XNA game in 2007. The developers found that using C# and XNA made the project more stable and productive compared to unmanaged languages like C++. While XNA provides good tools and abstraction, it has weaknesses like poor Xbox performance and lack of standard animation formats. However, its community distribution model through the Creators Club is unique in allowing independent developers to publish on Xbox Live Arcade with revenue sharing but no publisher involvement.

1. GRAVITRON ULTRA XNA

2. What is Gravitron Ultra? Multiplayer space shooter Single screen, two teams Battle for Orbs

3. (SCREENSHOT)‏

4. Development Less than three months, 3 people Steve, Niklas, Christoffer Not many bugs (pretty stable!), alright performance

5. Awards Won ”Best XNA Game” in SGA07 Won ”Best XNA Game” in .NET Awards 2 nd place in Dream, Build, Play 07

6. Postmortem – what went right: A working initial system design Message broadcasting across subsystems made encapsulation easier (could have facilitated network multiplayer!) (Kind of Object-C-like but with subsystems instead of objects) Prioritizing the right things (ditching network multiplayer) Using XNA / C# (managed) as opposed to SDL / C++ (unmanaged)

7. Worst-case scenarios in C# would mean working instead of sleeping. Worst-case scenarios in C++ could have killed the project outright General protection faults can be very depressing

8. Postmortem – what went wrong: Bad requirements, design not detailed enough As the deadline loomed closer program structure was abandoned in favour of ”hacking” HOWEVER, we managed to skirt disaster and finish on time

9. What is XNA? Managed game development framework for Windows / Xbox 360 (and now Zune) Integrates with Visual Studio Provides access to graphics, input, network, etc. Import assets via XNA Content Pipeline

10. XNA - PROs: Working in a managed environment! Decreases bugs Increases productivity High portability (MSIL) Performance – provides access to GPU, HLSL support Garbage collection, etc. is less of a problem than some might think Lets you focus on developing your game – Mature and extensive library (networking, windowing, etc. at a high level of abstraction) Visual C# - good IDE

11. Content pipeline – just import into Visual Studio Very good documentation! (for the most part)‏ Examples Best practices Excellent support through Creators Club Easiest way to make and distribute(!) console games, by far Nothing else even comes close It just works! Plugging in peripherals, deploying to Xbox – no problem!

12. XNA - CONs: Not as easy to deploy to users as it could be (will be adressed?) Poor XBox performance (due to the XBox CLR!)‏ XBox is built with high compile-time optimization in mind Abstraction starts leaking – many ”gotchas” XACT No support for MP3 or other formats (will be adressed?)‏ ” Fire and forget” sound engine, makes music games difficult to develop Weak support for character models and animation, could benefit from a standard format and dedicated tools (XNA is flexible, write your own content importer!)

13. Not cross-platform (No *NIX or Mac support)

14. XNA 3.0 (Beta)‏ C# 3.0 support Zune support Community features New sound API! (Music games, MP3 playback, finally?) Enhanched multiplayer One-click installer for Windows? (Not in Beta?)‏

15. Community Games

16. Create your XNA game Submit it to Creators Club (requires Creators Club membership) Your game gets reviewed by peers – filters out illegal or inappropriate content and ”broken” games Your game goes on sale on the XBLA Marketplace!

17. Revenue is split 70/30 between developer / Microsoft (not yet confirmed) No restrictions on who can develop No expensive devkits No licenses No publishers Nothing quite like it Online distribution portals (Steam, Gamer's Gate, etc.) are essentially just publishers willing to take risks The closest is probably Apple's App Store, but it is heavily moderated by Apple Community approval process – some level of quality control without expensive QA costs