Games like Helsinki Online

Lurkers is a chaotic 2D multiplayer sandbox where you can build, battle, and survive! In common: open world, sandbox, simulator.

Cataclysm: Dark Days Ahead (aka Cataclysm DDA or CataDDA) is an open source survival horror roguelike set in a post-apocalyptic and fictional New England. In common: open world, sandbox, simulator.

An exceedingly simple sandbox building-block game. In common: open world, sandbox, simulator.

A massively-multiplay world where players work together to build, farm, fish, and solve puzzles to fight back against the infectious Muck. In common: open world, sandbox, simulator.

A Life Simulation game with heavy RPG elements where you play as a Cow exploring, leveling up, and completing quests. In common: open world, sandbox, simulator.

it's a spaceship management simulation with space and crew combat, planetary visits, anomalous events, quests, and loot! In common: open world, sandbox, simulator.

BuildNow GG is part of an emerging genre of online game that combines tactical building with third-person shooter gameplay, featuring various game modes… In common: open world, sandbox, simulator.

Minecraft Classic is a JavaScript remake of Classic 0.0.23a_01, made to celebrate 10 years of Minecraft and was uploaded to the Minecraft website. In common: open world, sandbox, simulator.

Talewyn Harbor is a free-to-play multiplayer browser game set in a persistent coastal world. In common: open world, sandbox, simulator.

World Senate Game is an online multiplayer game in which you can have your own virtual life. In common: open world, sandbox, simulator.