Below is a link to a very bare bones game programmed in Python using the Transcrypt Python to JavaScript compiler.
It uses three.js on top of HTML5.
It's just meant as a proof of concept that browser games can be programmed in Python.
http://www.transcrypt.org/live/transcrypt/demos/pysteroids_demo/pysteroids.html
Note that while this is a very simple game, it's purpose is to show that browser game programming can be done in Python with
no runtime time overhead and virtually no space or pageload overhead.
Transcrypt is precompiled to JS and the runtime is only 20kB.
It can be source level debugged using sourcemaps and has things like multiple inheritance, comprehensions, metaclasses, operator overloading, optional static typechecking and strickt CPython syntax.