How many lines of code of each, how many people, how much work on which parts?

I dunno why, because I'm certain I've seen games like this somewhere, but this just seems really cool and sorta inspiring, along the lines of "hey, you can just write code and toss it in a browser and go". (Not to be rude; I'm sure it took a lot of effort.) This is one of the first times I've ever felt this way. Ever since '95, I've never been impressed with a web version of something, because usually it's a weak imitation of a native program. But this just feels like something different.