Well what I would add is:
1: Wool slabs
2: Weapons for the villagers, so when you attack one they will attack you back.
3: Grappling hook (like in Terraria)
4: More Bosses
5: Redstone that can be placed on walls and on the ceiling, as well as buttons that can be placed on the ground and ceiling
6: Horses (anywhere), eagles (mountain biome), sharks (ocean biome), bears (snow and forest biome), snakes (jungle biome), crocodiles (swamp biome), scorpions (desert biome) and rats that can eat wheat (they are travelling mostly through 1 block high tunnels in the dirt.
7: Dual Wield swords, shields, when you select a block instead of a weapon, the weapon goes to your back.
8: A lot more weapons! Battle axes, hammers, maces, blowguns, crossbows, staves etc.
9: More armors that look different, not just change the color of the iron armor. They can give bonuses like double jumping, increased speed, increased damage
10: Wings. They allow you to fly for like 7 seconds, then you start slowfalling to the ground.
11: Biomes like Hallow and Corruption from Terraria that can spread through the other biomes.
12: More dynamic! Make meteorites fall sometimes, armies that can sometimes come to attack you, make the moonphases actually change the mobs that spawn (for example, at full moon there are werewolves).
Yes, most of the ideas are from Terraria, because Terraria has a lot more things than minecraft, but it is 2D. So if minecraft would have all the things terraria has or terraria would become 3D, than that would be the best game eva!!!
