Games like Perpetuum

EVE Online is a player-driven spaceship MMO where your choices shape the universe. Experience large-scale warfare, exploration, piracy, crafting, trading, and a thriving player economy in a vast, persistent online world. Collaborate with others to build and fight for your own empire in a sandbox where consequences are real and lasting.

Astrox Imperium is a single-player space strategy game that lets you explore, gather resources, build space stations, and manage interstellar politics. Engage in real-time combat with AI-controlled ships while navigating a vast, procedurally generated universe. Experience an immersive narrative with multiple branching storylines based on player choices.

Dual Universe is a sandbox MMO set in a continuous, single-shard universe, allowing for a seamless player-driven economy and massive cooperative or PvP battles. Players can gather resources, craft and trade items, construct stations and spaceships, and explore or colonize the infinite procedurally generated universe. The game features a unique in-game programming language, allowing for customization and automation of ships, stations, and more.

"Ascent: The Space Game" is a sandbox-style space simulation game that allows players to explore, mine, trade, and fight in a vast universe. Construct and manage space stations, build and customize space ships, and form alliances with other players. Features a procedurally generated galaxy with thousands of star systems and planets to discover.

The Repopulation is a Science Fiction Sandbox MMORPG in Late Alpha Testing, offering a variety of roles and activities with a focus on player-driven actions. Despite being in an early stage, it provides a vast game world for players who are okay with bugs, possible service interruptions, and fluctuating features. This game is for those who enjoy massively multiplayer experiences and are willing to put in the effort for grinding and overcoming numerous bugs.

Ryzom, also known as The Saga of Ryzom, is a free and open source massively multiplayer online role-playing game developed by Nevrax for Microsoft Windows, OS X, and Linux.

In the sandbox MMORPG, Xsyon: Prelude, players are survivors in a post-apocalyptic world that has reverted to a medieval state. Set up camps, scavenge for resources, and craft items to progress, while interacting with a living world and other players in this unique virtual world. A website account is required to play and participate in the game's community and development discussions.

"Gloria Victis is a medieval MMORPG with a focus on non-target combat and large scale PVP. Explore a vast open world and choose your path, be it a knight, archer, blacksmith, merchant, or any other of the many available professions. Join the battle for territory and fight in epic wars, tournaments, and castle sieges."

"Star Conflict is a free-to-play, massively multiplayer space simulation game where players engage in combat as elite pilots in a war between factions. The game features intense PVP and PVE battles, a sandbox mode, and a wide range of customizable spaceships. With a variety of tactical roles, modules, and the ability to manufacture ships and modules, Star Conflict offers a rich and immersive experience for space combat enthusiasts."

CryoFall is a sci-fi open world colony simulation game where players can choose to play in PvE or PvP mode. The game features massively multiplayer options, including co-op and single-player, with good game mechanics and awesome graphics. Starting with primitive technology, players must progress towards modern industrial and space-age technology while building bases, farming, and exploring.