Earlier today, I was bored and browsing the XBLCG front page on the dashboard, and "Shield Defense" caught my eye from the New Arrivals section. I downloaded the trial and began playing it, and was really getting into it. Then I noticed something. It was not stopping me from playing, and it had been well past the allotted 8 minutes. I played through the entire game, all 25 levels, all the time expecting to at any moment be booted to a buy screen, but never was. It took me about an hour all told. To my knowledge, I did not buy it, or buy anything at all today from the marketplace, or do anything special except play the trial game mode. I have not gone back and tried to play it again on my XBox, but I did download it at my friend's house and receive only the usual 8 minutes of play time. I was wondering if this was a glitch anyone else has experienced with this or any other game, or if it's just me. (This has not happened in any other games I have downloaded off the service.) If it is a recurring phenomenon, it should be addressed at once by the microsoft team, as no developer can expect to sell games if their games are already available for free. If it isn't, and it turns out I was accidentally charged 400 MS points without my ever intentionally buying the game, or even going near a buy screen, this is an even more critical issue.
I have just a regular XBL gold account, no creator's club premium membership (at least none that I payed for).

i've had it happen to me occasionally when trying to run games in Trial Mode, just a glitch. it'll probly act normally the next time you try playing it.

Yeah, that's a known glitch that can happen with any of the games. Nobody knows how to replicate it, though, it just happens 'randomly'.

So no one knows why it happens?

The message box that automatically pops up when the 8 minutes is over is handled by the XNA software on the xbox, so the problem has to be fixed by Microsoft. They're already aware of it, and suspect that in the majority of cases it's people accidentally purchasing the game without noticing. It's very easy to do accidentally, which is why I double-check that the points cost of the trial I'm downloading reads 'Free'.

I've read posts on other forums of people having the same problem - they get confused as to how to exit the Purchase screen and end up buying some content they didn't want to.

But apparently this problem does exist. This is why it's important to not rely on MS's Trial for your game. If your only upsell is the Trial timer then you're very vulnerable to errors like this, and you're definitely losing purchases due to lack of good upsell. I can't count the number of times I've commented on this in Playtest and Peer Review... If you have LIVE features in your game, it's somewhat easier since these are locked by the Trial.

Unless the game was functioning as if it were the full version in this case?