TMNT Training Lair is free on Xbox Live. It looks like it's just permanently free since there is no trial. It was released yesterday (July 22nd).
I haven't tried it myself, but it looks to be similar to Fruit Ninja. The price is right; maybe you'll have some fun with it.
Link here.
In case anyone is interested, I just checked the site and both DMC and Metal Gear Revengence are in stock. I just ordered mine. I'm guessing they will quickly be OOS again like in the past.
Yeah, I checked a few other retailers' sites just now and none seem to have dropped price to match Target. Glad I happened to be up early on Sunday to pick up a copy then.
Keep in mind that last week's hurricane Sandy has affected shipping routes. Shipments of the LE copies may take some extra time if you find your store OOS.
The Xbox 360 version is just over $40. Seems like a decent deal if you're looking for a second guitar. I may bite. I could probably get a little bit back for the game on ebay since I already have it.