Blockland vs Salem
Blockland
Blockland may be a voxel-based sandbox game in name, same as games like Minecraft, Roblox and others, but in reality, the game is a whole lot more unique due to its Lego-like features. In fact, due to its looks, many have likened the game to the unfortunately shuttered Lego Minifigures Online. Playable in single player or multiplayer, the game allows its players to unleash their creativity by creating literally anything they can think of. The game also has tons of different blocks, textures and assets (pre-made stuff) to cater to their creative needs, allowing players to come up with the most exciting mini-games and mazes as well as beautiful locations for themselves and their friends to hang out at. Players can even drive cars (sometimes vertically up the wall of a building, breaking all rules of perceived gravity in the game), ride bikes, pilot planes, and more.Although the game is no longer getting updates and apparently its community has been dwindling, Blockland is still an amazing game that answers the question of what Minecraft would look like if its "Lego-fied". A blank canvas await you in Blockland! Do check it out - you can try the demo for free - when you can!
Salem
Salem is an old-school and somewhat obscure (but fun) sandbox MMORPG that unlike Wurm Online has a stronger emphasis on its in-depth crafting system and survival aspect rather than building.Similar to Wurm Online though, Salem is not a voxel-based game, but you are still able to mold the game environment through resource gathering, mining and digging in a way that reminds me of the currently-shelved MMORPG, EverQuest Next: Landmark. Of course, although not exactly the focus of the game, you can still build your homestead and the process is quite similar to Wurm Online except that it occurs at a much higher speed.
Not to mention, the game world in Salem is simply humongous to the point where it feels like an actual world. Salem also borrowed some features from ArcheAge where open-world PvP is the norm, so you'll need to be vigilant at all times, but players who kill and steal for no reason will be labelled as criminals and can be punished.
However, as good as it is despite being an indie MMO and all, Salem does have its fair share of flaws due to its low development budget. So, we'd recommend you to take a look at Salem without carrying along any high expectations. It's a pretty good MMORPG like Minecraft, but if you're expecting a Minecraft clone, you may end up disappointing yourself.