Cubelands Alternatives

Minecraft is a sandbox game that revolves around using building blocks to create anything you want. At night, monsters come out; make sure to build a shelter before that happens. The game also has multiplayer capabilities.

Minetest is a near-infinite-world block sandbox game and a game engine, inspired by InfiniMiner, Minecraft, and the like.

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.

Garry's Mod is a Sandbox Game based around the idea of building. Unlike most other games there aren't any objectives - you can't lose and you definitely can't win. Doesn't work on MacOS 11.15 or higher.

Dwarf Fortress is a single-player fantasy simulator. You can control a dwarven outpost or an adventurer in a randomly generated, persistent world.

Infiniminer is a multiplayer block mining game with several different player classes to choose from.

Manic Digger is an open-source implementation of block-building games, like the famous game Minecraft.

MineDroid is a viewer / concept design for Minecraft that supports using your own 1.3 beta levels, temporarily building and destroying blocks, sensor steering, crouch jump, ghost mode / fly mode. more features to come, you can get the source and help out too

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.

Gnomescroll is a multiplayer survival RPG in surreal environments. Kill demons, raise puppies and collect rocks.