Everyone's played shooters. For example, everyone remembers Gradius, right? Wasn't Gradius fun?
Replace the spaceship in Gradius with either a John-Woo-style Maid, or girl that shoots a streaming Kamehameha blast as her main weapon, and mix in about 50 billion more flying pieces of ammo from various enemies, and you get something approximating Gundeadligne.
They say a picture is worth a thousand words. Here's six.
http://www20.cds.ne.jp/~murasame/games/gundeadligne.htm
If you're good at shooters, you may get to see some of those stages. I'm not good at shooters; I regularly get my butt kicked on Novice Level, and can't help but get anhillated on 4B. Oh well.
Anyway, if you're looking to try it out, there are a few torrents carrying v1.01 everywhere, but out of respect for the fact that it's still being sold commercially, I won't post those links. However, at the end of the link I have already posted, there's a demo.
Neat... if I wasn't swamped I'd check it out.
Dracos