In case it's not disgusting enough from a god's eye view, you can actually play Alien Swarm in first person fairly easily. I've just tried it, and it's a bit of a shock. Here's a video of what it's like to play, and instructions on how to do it yourself. It only takes a sec.
You can pretty much see what to do from the vid, the only extra bit of information you need is that to bring up the console, you have to go to Options > Keyboard > Enable developer console. Then hit ` (to the left of 1) and type:
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