So, one of the essays I found useful in the Escapist was the one on shmups. Specifically, the link to Torus Trooper.
This game is very nice. Fighting on the inside of a tube feels like the most natural thing in the world. But this game is also very "pure". There's no power-ups, no crashing into walls. There's not even any homing bullets or things that change velocity. The whole game consists of dodging bullets and shooting people, at as high a speed as you can manage.
It's got some interesting dynamics! For example, never play it on the lowest difficulty setting. In all the other modes, the ship moves at just the right speed to avoid waves of bullets in a zen-like fashion. In easy, however, the ship moves wrong, and you actually have to keep track of every bullet. Pain in the ass.
I didn't know there was a charge-shot. I hate the fact that games like this insist on having one. I don't like to use it, because it's primary purpose is to kill bullets, and I don't have a hard time dodging bullets. I had a great time without it: the zen-like maneuvering is what I'm after, screw the specialty weapons.
Anyhow, play it.