Eggo said:
Quite a few, actually. [http://www.kongregate.com/]
And last I checked, I'm not alone. But that's not the primary point I'm making, although this ancillary point only supports my view even more!
They are great, aren't they? [http://www.jayisgames.com]
Sorry, my point is not games you play IN Firefox, but that browsing the internet isn't a game. Not really the important part of my argument, but I wish more people would take the online flash game community seriously. There is a lot that is done there.
The aiming component in FPS games, just like the HID component in navigating a modern desktop internet browser (along with OS) is 2D. In terms of user interface analysis, they are extremely similar.
As far as pointing at things and clicking on things, sure. But your character doesn't stand in one spot, he traverses through a simulated three dimensional world. moving through a browser uses only one device at a time, either clicking or scrolling, or typing in an address. A 3d first person shooter relies on two simultaneous devices to navigate, constantly. I know I don't take my hand off the keyboard to shoot, or take my hand off the mouse when I am running through the world. Additionally, there is no penalty on the internet for poor dexterity. If you don't click on a website in a certain time frame it doesn't close down the browser and make you start over. Nothing while browsing can be based on reflexes.
OK, I guess I missed it, I'll go back again.
EDIT: Oh, OK, I see what you're getting at about the movement. I kinda skipped that part because it was already pretty obvious. I will, however, say that Metroid Prime had the most fluid movements of any controller, even a mouse, although that's partly my fault because I'm jumpy when I play FPS's. It has a really nice analog smoothing of the motion that is the only time FPS gaming has felt natural on a console.