The Rise of Magus can be played on the Game Maker site now at:
There are several nice things about this. For one, it means the game is available even when my site is down (which it apparently was an hour ago). It also means that it's possible for users to play the game without having to download the .exe file (if they install the yoyogames plugin, they can play it off the site), which will hopefully make people less scared of trying it (and I wonder if that works on macs - I should test at some point).
Also, the site keeps track of how many people are playing it and what score they gave it, so that makes it a useful source of feedback for me.