No way it could be done in 48 hours. Getting the level achievements alone will take up to a month based on skill and time available.
For the people that play well AND have time on their hands, they're still getting the level achievement in about 2 weeks. It will be even harder now that the game is not brand new and the players are all familiar with how to play the game.
U N B R E A K A B L E !
A loyal fox with all of Sonic's 360 achievements!