Ace of Spades: Battle Builder!

Unturned is a sandbox game in the emerging multiplayer apocalypse survival genre. Rather than focusing on being an MMO it provides players with easy systems to sit down and survive the zombie infestation with their friends. Over the course of a typical adventure, groups will have a blast fortifying locations, scavenging for supplies, trying to live off the land and negotiating with other people.

The Fun-Focused Free Software Voxel World Game.

Creativerse is a sandbox adventure game set in a beautiful yet treacherous world shrouded in mystery. Adventure solo or bring your friends, unearth secrets, and tame the land together!

I have said a few times that Epic Inventor was inspired by Terraria. There are obvious similarities you can see right away in the various screenshots I’ve posted. Certainly our desire to create a game was inspired by it as well. We love that game. We played it a lot.

OpenSpades is an open source OpenGL-based alternative game client by yvt that can be used to play on all AoS 0.75 and AoS 0.76 servers listed on BuildAndShoot.com. It's compatible with PySnip/pyspades and runs on Windows, Mac, and Linux.

Minecraft Clone to PSP

Blockland is a non-linear sandbox game with no set goals, giving players the freedom to design and construct elaborate structures. Styled as a tiny minifigure, players build inside of the virtual world using bricks reminiscent of toy blocks. These structures can be built in either a single-player or multiplayer (either online or through a local area network) setting.

Manic Digger is an open-source implementation of block-building games, like the famous game Minecraft.Manic Digger aims to be a generic platform ontop of which you can create your own game-types and scenarios. Through server-side scripting, almost any type of block-building game should be possible.

This sandbox fun-shooter allows players to create worlds and maps that they’ve always dreamed of, brick by brick. They can share these virtual playgrounds with the community and use them as the backdrop for fast-paced shooter hunts against fellow players or computerized opponents. This comic style online game is built on the ‘Unity 3D’ engine and will be playable directly in a web browser. The ‘sandbox’ mode, in which players use simple building blocks to construct complex environments, can be played on social networks and mobile devices such as smartphones and tablets. Brick-Force is being developed by Korean game developer EXE Games as a co-production with Infernum. Beta and launch of the free-to-play title in Europe and North America are planned for spring 2012. »

The website linked is not real page, just moddb page. Wikipedia says all official sites have been closed.This program is now available online for free at abandonia.com.

First Person Shooter! Dynamic cubic world where you can build and destroy things and ones. Modern, real prototype of weapons and other liquidating your different-colored enemies will vary your in-game possibilities. A lots of cool game-modes, where you can shoot, destroy, build your own map, be the last-man-standing against zombies in Zombie-Mode, or to arrange a massive tank battle in Tanks Mode. Every one can find stuff he addicted to in this game. Huge amount of maps, made by developers themselves and of course by community. Upgrade your weapon, your looking, and looking of your equipment, increase your in-game level, involve yourself in the game's worldwide ranking system with another players. Some of game-modes include up to 4 team at the same battle field. Clan tournaments where you gather with other clans to reach 1 goal - be a champion. »

Infiniminer is a multiplayer block mining game with several different player classes to choose from.The object of the game is to collect loot while trying to keep the other team from accumulating loot.

Block Story combines a mineable blocky world pioneered by Infiniminer and made popular by Minecraft with exciting and addictive role playing.