Found this video while fiddling around on YouTube. Pretty lengthy too.

Soo...yeah, from the video, this is what I can gather:

• A new file (perhaps) in the VIP Room of the Casino stating an egg of some sort.
• Not long after the reading and on the way to the bilge, there seems to be some sort of egg.
• Puzzles are done maybe using the analog stick and buttons. Haven't seen how to un-screw the screws though, probably spin the analog stick I guess.
• The Genesis returns with altered interface.
• Weapons now have descriptions in the Customization Bench menu.
• The MP5 seems to have a buffed up firing speed, from 1.67 in the 3DS to 7.50 in the HD Port. (Ain't that ridiculously fast...)

That's all I can gather from now, if there are anything that I have missed, feel free to comment.