GRAVITRON ULTRA

XNA

What is Gravitron Ultra?

Multiplayer space shooter

Single screen, two teams

Battle for Orbs

(SCREENSHOT)

Development

Less than three months, 3 people

Steve, Niklas, Christoffer

Not many bugs (pretty stable!), alright performance

Awards

Won ”Best XNA Game” in SGA07

Won ”Best XNA Game” in .NET Awards

2nd place in Dream, Build, Play 07

Postmortem – what went right:

A working initial system design Message broadcasting across subsystems made

encapsulation easier (could have facilitated networkmultiplayer!) (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)

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

Postmortem – what went wrong:

Bad requirements, design not detailed enoughAs the deadline loomed closer program structure was abandoned in favour of ”hacking”

HOWEVER, we managed to skirt disaster and finish on time

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

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

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!

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!)

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

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?)

Community Games

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!

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