What were your conclusions?
Google terms of condition said that AdSense is for website, it is not permitted to make content with ads dedicated to a third party program.I understand you can display a part of a website in an application, but any content displayed need to also be viewable with a standard browser the same.
Ads need to be displayed strictly like Google define itSo it involve a full standard compliant HTML/javascript engine. Of course this engine need to be GPL compatible (mozilla embedded ?).
Display of ads, or click on ads can't be triggered by any third party programI understand that you can't display ads directly by launching the game or connecting to a server. The display or click must be triggered by the visitor himself. Like if you add an optional panel in menu with message of the day or community information.
Of course ads need to be click-able, but it is forbidden to launch a separate application when clicking. So, no minimal HTML engine for displaying ads in-game that launch the default browser when clicking.
Google talk a lot about third party program in it's term and conditions. But it doesn't clearly exclude browser embedded in application. What they exclude is "clicker bots" and any application that can bias the intended purpose of their ads program (non intrusive contextual advertising).
The AdSense terms and condition let all power to Google for stopping (and not paying) when they want without any justification. The simple fact to add the message "click ads for support us" on your website and you will be removed without indemnity. So if they discover an unconventional use of their ads, or a poor ratio between ads displayed and clicks, they can stop immediately. Of course, most cancellations are done by some Google robots and verification algorithms

My conclusion is that embed a web browser and display ads in a software is not forbidden by Google but will be very hazardous and could result in a cancellation without any explication. If the content need to be also available to every visitor of the website with a standard browser, so it's probably more simple to create good contents on a website and add some ads.
This website and this forum are an example of good content

A good player account and statistic system viewable from the web could produce interesting content and be a good place for server admin to add some ads.
Excuse me if the start of this thread has choked some Tremulous players, my intent was purely to increase my knowledge on this subject. I am personally hostile to advertising during the game party itself. But if non intrusive ads are placed in pre-game menus...