
The game will allow you to swop any of the hidden eggs you found in Banjo Kazooie at Heggy's Hen for brand new moves that were not on the original N64 version. Here's a little video that came out a couple days before Easter that shows you a preview of the stop n swop and where to find any of the eggs in case you missed them.
Also a list of all the achievements can be read here if you're interested.