There's also the secret minigame that didn't get carried over. There are various maps that can only be accessed from the old menu, besides the new menu's store, since they didn't get introduced.
Well yeah, I think it should be above the Math Level in the selection screen, and also a bit updated.
But I think the store alone is already too broken for new players or other players who might think it's fair. In fact, come to think of it, you can LITERALLY PURCHASE UNTITLED MAPS WITH ARTIFACTS IN THEM FOR AN EVEN LOWER PRICE, AND EVEN LESS EFFORT. I'll have to update my comment now...