Nicely polished game. Enjoyable and challenging to the end. It does feel like there is one optimal combination of three classes that works best, but finding out what that is part of the challenge.
In reply to developer comment: "Weird. What operating system are you running? Windows 7/MacOSX? Does it run if you try from http://www.playpixelvania.com ? Thanks for reporting!".
Running Ubuntu Linux 11.04 (most recent version), although that shouldn't matter with Flash games, I rarely encounter issues with Flash games. Firefox 6, Flash 10.3.162.29. The same happens on that website.
Please add a way to customise the movement keys; left-handed people often use the arrow-keys, and French language keyboards don't have the WASD keys in a triangle.
I have Ubuntu 11.04 running on a machine at home, will check it as soon as I can!