Terraria has guns, Electric Guitars, Grapplin hooks, Wings that make you fly (Jet packs too) You summon pet's using items such as cabbage and honey comb, you don't select a skin, you put stuff in your equip slot, you can make torches blink, they had Lanterns long before Minecraft, they had live Oceans long before Minecraft, it's more colorful, it's more vicious, they have NPC's that you actually know specifically instead of random Villagers, they don't have Nether portals, you go to Hell and Magic mirror your way back, the sky is a dangerous place. If you've even played Terraria past the Wall of flesh, you would know the proper explanation is that it's a mix between Minecraft & Adventure Time, that's actually what Inspired Minecraft to have an Adventure time Mash-up pack.