Rollercoasters have been added to the thrills in http://www.trueachievements.com/game.aspx?gameid=3648
via the new DLC pack released today.
Get more heart-pounding thrills, twists and turns in this new roller coaster downloadable pack. Grab gold coins as you race through ancient tombs and pyramids in Mummy Madness; get spaced out in Galactic Express; and dodge medieval mayhem in the fiery Dragon’s Den!
The pack has five new achievements worth a total of 125G, but there are problems with unlocking these at the moment. The achievements HAVE NOT been added to Xbox.com; therefore any players unlocking the five achievements now will find that neither their gamerscore nor their number of achievements earned will increase. We advise that you wait for the achievements to be added to xbox.com before trying to earn them, and we will give you an update when this occurs. If players have unlocked any of these achievements before xbox.com is updated, then your gamertag will have to be recovered and the achievements earned again for them to be counted properly.
The "Coasterama Pack" costs 320 MSP and can be downloaded from here