So... you stumbled here because of my video replays on Google Video or Dailymotion or Youtube eh? Or maybe you saw my "got danmaku?" banner. Want to learn more about the game? Well, here are some links for you!
First of all, the video clips are from a game series made by a single guy called ZUN. Yep, he makes the engine, draws the characters, and composes the music. Then he sells it for around 1000 yen at the Japanese comic markets. It's so popular that it has its own conventions and clubbing events (see flyer below).
His site is at http://www16.big.or.jp/~zun/ - you can find the demos on the site, although you may have trouble finding the links if you don't understand Japanese. He also has a blog at http://kourindou.exblog.jp/, which is the only place to find info on the Shoot the Bullet game. He also talks a lot about alcohol there.
So, the next stop you'll probably want to make is http://www.shrinemaiden.org - this is essentially the main English fansite for the game series. From there, you should be able to find everything you need to know about the game, like guides on scoring methods, a forum for you to ask questions, etc. Also join us on IRC at irc://shrinemaiden@irc.pyoko.org
And lastly, if you stumbled here from somewhere else and don't even know what videos I'm talking about, just use this embedded player to see the videos.