well i always wanted to do this and now i have the chance to ill be starting out with xna and hopefully get a game published by the end of next year so i need some ideas i was thinking of

platforums like cloning clyde or crash banditcoot
old shooters like- contra
arcade shooters- geometry wars or galga

please give me some ideas and possible games that you might want to see and if you already do xna can you help me out ?