I can give you other ideas:
-character customization
-fishing mode
-bows, arrows
-caves (you can enter it by some kind of structure)
-minerals
-going upstream in water slows you down and the same around
-farming
-stairs (like you can go higher and lower in layers)
-classic colored blocks
-beds (skip the night)
-some kind of armor
-gems and collectibles
That is probably all that i can think of. Let me know if you are interested in adding one or many of theese ideas.