Video Game Design/Process
Before you consider implementing your design one thing that you should ponder as you consider implementation is how costly it will be, in time and money. You can monetize you game design (concept) by selling it to a game creation studio, or you can create an open source project for open implementation.
As you consider what to do, take also in consideration the marketability of the game you created and your objectives. Is it going to be free or are you selling it? If you are selling it, will people want to buy it? How are people going to hear about it? How much money and resources are you willing to spend on marketing this game? Do you have them and are they worth it?
The implementation should also be seen as a sandbox where things will be tried out and pruned to meet the required objectives. You should only get worried in the later stages of implementation since at some point one must accept that too much changes will probably ruin the project.
If you stall in some section of your implementation, go back to your design references a see on how others before you handled the issues. You can, and should, be creative but you should expect that the someone has already found at least a workable solution to every issue, use you creative resources to build upon that in place of recreating something equal to what was already done before.
Concept vs. ability
Before you begin developing remember to discern between what you want to do, and what you actually can do. Figure out the resources that you have and compare them with the resources the project will require and adjust accordingly. If you have a lot of resources but your concept is simple, perhaps you could expand it. And if you have a complicated concept but simple resources, maybe you need to expand your resources.
After you have gone through all of these considerations outline the project, first by how the game will work and how it is arranged then chronologically by how you are going to accomplish those things - it might be helpful to set a due date for yourself.
Consider your resources, what abilities do you personally have? Can you program, draw, and render a polygon? How much money do you have and how much time are you going to spend on it? Do you have the technology to build a game or do you need to get it? Do you know what you need?
A video game is a really big project for someone to take on, especially just one person. It may be a good idea to do the project as a team bringing together all the resources you need to put together a good video game. It is almost impossible for only one person to create a game that people will actually enjoy. Being in game development requires you to have good social skills, because 99% of the time you will be working with a team of designers. It Is important that you build a friendly relationship with your fellow game designers to get the best results of a project.
The testing and development phase are where the game is actually created. As you program, make graphics, compose music and collaborate these resources you will have a lot of testing and debugging to to do. Consider the following sections.