Terraria....

It's hard to not compair Terraria against Minecraft. Both have block worlds where you harvest wood with axes and ores with picks. They are vastly different games.
While I've been playing Minecraft for years on and off. I did knew Terraria was out there but dismissed it quickly taking 3d graphics over 2d and not looking into any other details. I was so so wrong to have done so.

 

Terraria is a much more fun game.

I'm glad I picked it up for less than €3, that's not to say I wouldn't have paid more for it.

Where minecraft is all bout the building and the blocks, Terraria is all about the adventure.
"Stuff" be it blocks or items is secondary in Terraria, not inconsequential but you seem to work harder in Minecraft for not a lot or payout.

Minecraft has you looking up sites to see what you can make where Terraria shows you what you can make and what you need to make it with. And you have it there and then. It's a much better crafting system.

The addition of Terraria on Steam has made multiplayer an easy feat. Where I believe it was more complicated in the past. Now it's a few clicks between hosting a world and inviting a steam friend.

The fun side of Terraria is best shown when you can have a yo-yo as a weapon, upgrade it to have better damage as well as pushback against enemies and add on special items like "lucky string" to buff it again! As fun as the yo-yo was I did change it for the flail, more damage is always better.

Minecraft never had a cart/rail system like this:

 

But the older trailer is a better gauge on the game, I wish I'd looked harder when I heard about it first.