Games like PHYSARUM: Slime Mold Simulator

"Creatura is a simulation game in early access, available on STEAM, which allows players to design and manage ecosystems with scientifically accurate natural and artificial selection. Create and evolve your own fauna and flora using DNA editing tools like CRISPR and GMO, and sell plant cuttings to buy decorations and consumables. The game features one open-ended 'sandbox-like' mode with beautiful bonsai-style vivariums and a goal to fulfill a unique almanac of species."

Townscaper is a relaxing and creative town-building simulation game. Place and connect different types of buildings to design your own colorful and vibrant seaside town, with no need for resources or scores. Experience the joy of watching your town grow and evolve, with charming details like boats, parks, and winding streets appearing as if by magic.

FlowScape is a single-player, violence-free game that allows players to create their own nature scenes by painting with over 300 models and 20 landscapes. With advanced paint options, physics, and the ability to import custom models, players can build their own private paradise and add life to their landscape. However, it has been noted for its grinding gameplay and occasional bugs.

"Ecosystem is a single-player strategy game with high-quality graphics and approximately 23 hours of playtime. The game's unique feature is the simulation of evolving virtual creatures, whose bodies, behaviors, and nervous systems are all determined by their synthetic DNA, which can be modified by the player. These creatures evolve on their own to adapt to the physically-simulated ocean environment created by the player."

"Marble World" is a 3D platformer game where you control a marble and navigate through various levels with different obstacles and challenges. The game features a level editor, allowing players to create and share their own custom levels. Gameplay involves physics-based puzzles, accuracy, and quick reflexes to roll, jump, and bump your way to the goal.

Tiny Glade is a relaxing free-form building game. Tap into the joy of making something pretty with no management, no combat, or wrong answers - just kick back, doodle some castles, and turn forgotten meadows into lovable dioramas. Explore gridless building chemistry, and watch the game carefully assemble every brick, pebble and plank, adapting to your whim. Draw a path through a building? A door …

"Behind Glass: Aquarium Simulator" is a PC game that allows players to design and simulate their own aquariums with lifelike fish, crabs, plants, and decorations. The game features a 3D aquarium engine, realistic 3D effects, and the ability to display the aquarium on a secondary screen. Players can choose from 102 species of fish and crustaceans, create hybrid species in the crossbreeding lab, and share their creations on the Steam Workshop.

"Logic World" is a sandbox game that allows players to build complex logic circuits and machines using a visual programming language. Players can design and test their creations in a 3D environment, with various components and tools at their disposal. The game also features a multiplayer mode, where players can collaborate or compete in creating the most impressive logic designs.

"Block'hood" is a single-player simulation game with stellar gameplay, awesome visuals, and outstanding music. As a city planner, you'll create unique neighborhoods from over 200 blocks, while managing resources and avoiding decay. The game encourages experimentation and understanding of ecological city dynamics, but can be bogged down by bugs and requires grinding to unlock new blocks.

"The RPG Engine" is a sandbox role-playing game that offers players the freedom to create their own adventures. With a focus on user-generated content, players can design characters, quests, and worlds using the game's robust engine. The game features a variety of tools and customization options, making it an ideal choice for players who enjoy creative control and storytelling. Please note that the game is still in early access and may have some bugs and unfinished features.