A friend of mine pointed this game out to me last night. I didn't get to bed until like 2 AM.
The story isn't super-amazing. You're some kind of cyberninja girl and Earth has been invaded by aliens. Shoot them. Oh yeah, there's a bunch of dialogue with some angst about being an unwilling hero and stuff. Whatever. You have a shotgun and can kick dudes to death.
Also, later on, you get lasers that explode when they hit things. It's pretty badass.
It's basically got 3 parts crammed together: RPG, action and platforming. The platforming (and smooth, smooth animation) is straight out of the old-school Prince of Persia. Run, jump, kick dudes in the head. The action is, well, platformy action. Duck shots, stand up, shotgun a dude to death. Or kick him. Or shoot him with a rocket launcher. Or a spread-rocket-launcher. Or lasers. That explode. The RPG bit... every stage you can gain up to 5 levels, and each level gives you a stat point. At certain places on the map, you can spend these points to give yourself more health, increase your ammo capacity/healing, increase your damage, increase weapon stats to use bigger guns, and a bunch of other stuff.
Apparently the story parts change up depending on how pacifistic/violent you are, but that interests me a bit less since there's fewer exploding lasers involved.
Homepage here.
Trailer here.
Oh yeah, and it's free.