Brick Hill is described as 'online UGC sandbox game where users can build with bricks in a voxel style 3D building environment, play on multiplayer servers, purchase virtual items for their avatar with virtual currencies, which are known as "Bits" and "Bucks", and'. There are four games similar to Brick Hill for a variety of platforms, including Windows, Mac, Android, Android Tablet and BSD. The best alternative is Minetest, which is both free and Open Source. Other Brick Hill like games are Roblox (Freemium), KoGaMa (Free) and WorldToBuild (Free).
Roblox allows you to create games, build whatever you want with lego-like bricks, play other games made by users of the community, and even participate in the economy by trading, selling, buying, and collecting items.