You could upload your games to dropbox, get the game's url from dropbox, then include the game in an iframe.
As an example, I can include my own game in an iframe like so:
<iframe src="https://dl.dropboxusercontent.com/u/41325628/nibble2/index.html" height="550" width="550">
As with WordPress.com blogs, I don't think there's an easier way than this.