First of all, welcome to the community. Creating games can be very exciting!
Secondly, for this particular platform there are certain skill sets that are required.
1. You must have a decent understanding of programming and specifically in C#
2. You either need someone who can create art assets for you, or have the skill set to create these assets in a 2D paint program like Photoshop, Expression Design, Paint Shop Pro, etc.
3. If you want to create 3D characters and export them as a 2D sprite, you (or someone on your team) will need to understand how to use a 3D program such as XSI Mod Tool, 3D Studio Max, trueSpace, Maya, MilkShape, Blender, etc.
4. If you want music and sounds you will need to either find a musician or use software to create music like Sonar, Sony Acid, Super Duper Music Looper, etc (My knowledge on these is extremely limited, probably much better choices). You can also find public domain sound files on the web.
5. You need some sort of "Game Design" skillset such as creating a story, determining difficultly level and how that should increase over time. What the goal of the game is. How do you reward the player to keep them interested and whole host of other things to think of.
6. You need to understand the XNA Framework (XNA Game Studio). There are a lot of resources online and in book form on this subject. Most won't do you much good until you get #1 (learning C#) on this list nailed down though. This framework does a LOT of heavy lifting for you compared to how things used to be done. However, it still takes programming skills to get things done.
I certainly hope the above list does not discourage you. It is a lot of work - making games takes a lot of work - but being able to play something (and have your friends play something) that you made is pretty cool. So if you really have a desire to make a 2D side scroller, don't let anything stand in your way and start learning C# and then move to learn XNA Game Studio while gaining knowledge in the other areas mentioned (2d art, 3d art, sound, music, game design).
Good luck and Happy Learning!
Chad
Chad Carter
Microsoft XNA Game Studio 3.0 Unleashed - Book contains information on 2D, 3D, HLSL, Content Pipeline, XACT, Particle Systems, AI, Physics, Game States, Performance, Zune and 4 full games (2 of which are multiplayer)!
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