Besides the H&M and IKEA packs not being included, /supposedly/ the game is meant to fix bugs that wouldn't allow people to play on newer systems. So far however I've seen a lot of people having issues with their games so far, myself included. I do technically Have the ultimate collection (though not downloaded at the moment) so I can say for sure that you're able to enable shadows without The Boxes and I haven't noticed any screen glitches on the legacy so far. Gameplay itself however isn't working for me.
