Minecraft is not only about building and has indeed some gameplay. Actually it is quite simple but similar to games like Diablo. In Diablo you click, click, click (to destroy enemies) and then they drop loot, you collect it and click, click, click, collect loot, click, click.. later you use the loot for some crafting.
In Minecraft you click, click, click to destroy world blocks. You collect loot (resources) and you do some crafting after it. Besides that you have some enemies to defeat. Terraria works the same way.
A space simulator also works that way, you can kill enemies, collect loot and improve your ship later on. In games like X3 you can even build space stations, factories, new ships and much more.
The difference to minecraft is only, that the building process is reduced to a combination of simple blocks and thus comes with a higher degree of freedom. But the gameplay is existant and not much different than in other games.