I decided to start Metal Gear Rising (PS3). The combat is very good (as you'd expect from Platinum Games), but I had to look up online how the parry system works since the game does a very poor job of teaching you how to do it. Outside of combat, the game feels like a Metal Gear game due to the unbelievable amount of recorded dialog for the optional codec conversations. I played the game for over four hours, and at least 75% of that time was spent listening to the optional dialog. I have no idea why they recorded so much additional content that few players will bother listening to, but if you ever wanted to be lectured about the history of the Georgian republic, this is your game.
I also tried three more demos:
Castle of Illusion Starring Mickey Mouse (360)
-A good looking platformer with somewhat touchy controls and excessive voice narration. I've never played the original, so I can't comment on how it compares to the Genesis game.
TMNT: Out of the Shadows (360)
-Exceedingly mediocre brawler based on the Nickelodeon show. Avoid.
Brothers: A Tale of Two Sons (360)
-A quiet game about two brothers looking for their father in a pastoral landscape. You control both brothers simultaneously; one is mapped to each stick and each has a context sensitive action that can be performed with the trigger closest to their stick. Seems pretty good, but the demo is too short to say for sure.