Microsoft has just launched their Live Games on Demand service for the PC, and they have a a free game for anyone that tries the new Games for Windows LIVE Software.
 
The game is called Tinker, and it is a pretty basic puzzle game where you control a robot to the end of the level. Here is the official description:

 He's little, he's metal, and he's lost.

Being a small robot isn’t always easy. Being a small robot marooned in a surreal world of clockwork, inventive mechanisms and challenging puzzles, even less so. In Tinker, a free puzzle game that pushes the boundaries of robot deduction, you’ll guide your robot through switches, contraptions to reach the exit. He’ll only do what you command. He’ll only go where you tell him to. It’s up to you to get him home!

Featuring captivating visuals, an original music score, and 60 levels that range from the facile to the extremely challenging. Tinker is an isometric two-dimensional puzzle available for free. Tinker features a tutorial level to get you started. What are you waiting for? Get Tinker for free when you download Games for Windows - LIVE. Start Tinkering.

• Guide your small robot through 60 different levels of inventive mechanisms, switches, lasers, teleporters, and more!
• Earn Tinker Achievements only available through LIVE.
• Enjoy 3D graphics that enhance the majestic clockwork world!

The game is pretty fun, and it has 15 achievements worth 200 points through Games for Windows Live, so give it a try. Its like a free XBLA game but for the PC.
 
Game page on Microsoft Games:
http://www.microsoft.com/games/en-us/Games/Pages/tinker.aspx

Download the game through the client here:
http://www.microsoft.com/games/en-US/Live/Pages/livejoin.aspx 

Gallery

To bad I can't get the fucking game to install correctly.

Is it just me, or is the GFWL download queue a bit broken? It seems to randomly stop downloading, and I have to click pause & then resume to get it working again. Weird. Ah well, I'll get it downloaded eventually.
 
Are the achievements easy? I'd love to get another S rank on my profile.

I guess they combined my thread with another one.  I guess I'm not the only person having the error.
 
LINKAGE

BUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUMP!
 
I finally got the game to work!  I guess there is an Vista Ultimate issue for the game.  To get this working on Vista Ultimate, you have to uninstall Tinker that comes with the Vista Ultimate Extras.

Awesome, I'm gonna try to download it now.

My GFWL launcher never seems to work properly, GFLW works fine in-game (sorta, still can't download the DLC for Batman), but i can't launch the actual application.
 
would love to check this game out though.

I did not know this was free. I was planning on picking up World of Goo, but didn't know how much this one was. Thanks, OP. Hopefully it installs fine on Windows 7. Halo 2 has been nothing but problems.

The download now seems to be completely broken. When I go to download, I get a "Sorry. An error has occurred during the transaction. Please try again later" message. Anyone else seeing this?

Thanks.  There were some download issues and when it was downloaded, I had to get a .dll online for it to work. Whatever, free game.

" The download now seems to be completely broken. When I go to download, I get a "Sorry. An error has occurred during the transaction. Please try again later" message. Anyone else seeing this? "

Cool. GFWL just updated too, so I guess I should try this out.
 
- jump forward 10 minutes -
 
Seems to work. Downloaded, installed and playable! Thanks again for the heads up.

I absolutely cannot sign into Live through Tinker... anyone else having this problem?

" The download now seems to be completely broken. When I go to download, I get a "Sorry. An error has occurred during the transaction. Please try again later" message. Anyone else seeing this? "

got it downloaded fine and played the first 4 tutorial levels, though oddly the 4th tutorial level cannot be completed with all 3 stars....i've tried every combination and there is no possible way to get it in 17 energy units left.

I've gotten like 60G so far. It's a pretty fun game too.

I bought Windows Vista Ultimate 32 bit and I assure you, that game was already included.

" @WilliamRLBaker: That does not sound like the 4th tutorial level, it sounds like the 11th. "

yeah i figured i dont know why i said 4th level i cant remmber what level it was...but i just couldn't figure out how to get the par energy for it, i even did the show me solution adn followed that and i couldn't do par energy i cant remember what level it was now.

Yeah the GFWL client is messed up. I tried downloading the Batman DLC the other day and it told me the filesize was have of what it should have been and stopped downloading when it reached that. Then after removing it and attempting to re-download, it would never start downloading.
 
I had to go back and download it like I was doing it for the first time instead of using the download queue. This worked, but it duplicated the item in the download list. Once it finished downloading, it installed. Upon restarting the client, it back back to one copy.
 
While I was messing around with the batman DLC, I paused the Tinker download and forgot about it. Now I see this thread and start up the client again and there are two paused Tinker downloads. Unpausing one does not unpause the other and it starts downloading each separately when unpausing both manually. So I had to cancel both and start the download yet again.
 
This is the first problem I've had with GFWL in any form. I'm pretty sure I don't wanna use the standalone client again.
 
I just selected MSP instead of credit card by reflex. Luckily that was the correct option.

" @WilliamRLBaker: I bet it was the one that i linked in the previous post. It has the same requirements and i got stuck there to. "

I didn't have any problem getting  everything on the tutorial stages (maybe because I play a lot of puzzle games?), but it's good to see that there are YouTube videos out there for when things get tougher.
 
I've run into a bit of an annoying glitch, though. Now, EVERY TIME I complete a level, I "unlock" the achievement for completing the tutorial. Every. Stinkin'. Time. It's a minor thing, but it's just annoying that it pops up at the end of every level.

I can't download it, Games for Windows Live says there is no internet. Which is impossible because I have to be connected to the internet to get there.