LemonArcade
The game on this page is Orion Sandbox, a two-dimensional survival sandbox that borrows its whole design from Terraria and says so openly. It is not Re-Logic's Terraria, the 2011 game by Andrew Spinks that sold tens of millions of copies; that game has never had a browser version. Orion Sandbox was made by a small studio called EyesTeam as a Flash game for portals such as Y8, Kongregate and Newgrounds, and later grew into Orion Sandbox Enhanced, which reached Kongregate in April 2018 and Steam the same year. What you play here is the original Flash build, revived in the browser through the Ruffle emulator now that Flash itself is gone.
The loop is the one Terraria made famous. You spawn on the surface of a side-scrolling world with nothing, punch a tree for wood, build a workbench, craft a pickaxe and start digging. Every block can be removed and placed, so the ground under you is both the resource pile and the building material. Dirt and stone come first, then copper and iron deeper down, and each tier of ore unlocks the next tier of tools, weapons and armour at the crafting station. A day and night cycle sets the tempo: daylight is for gathering and building, and once it gets dark zombies and other creatures spawn on the surface and come looking for you.
That night pressure is what gives the first hour its shape. A shelter with a door and a light source keeps the monsters out, so the earliest goal is always a sealed room before the first sunset. After that the game opens up: caves lead to underground treasure and rarer materials, better armour lets you fight rather than hide, and the base grows from a dirt box into something with rooms, storage chests and farmed crops. There is no quest log or fixed objective, and the ending is whatever you decide it is, whether that is a fortress, a mine that reaches bedrock or a full set of the best gear.
Compared with the game it imitates, Orion Sandbox is smaller and simpler. The world is a single map rather than a choice of sizes, the crafting tree runs to dozens of items rather than thousands, and the monster roster is modest, though the Enhanced edition later added seven bosses and more than ten enemy types. On the other side of the ledger, a run here starts in seconds, the controls are learnable in a minute, and there is nothing to configure. It is the version of the idea that fits a lunch break.
It suits players who have heard about Terraria but never bought it and want to understand the appeal, anyone who liked Minecraft's survival mode and wonders what it looks like in two dimensions, and people who enjoy base-building where the threat is real but manageable. Terraria veterans will find it thin and should treat it as a nostalgic Flash curiosity rather than a substitute.
On LemonArcade it runs free in the browser with no download or account. Because it is a Flash game played through Ruffle, it needs a keyboard and mouse and is desktop only. The first load can take a few seconds while the emulator starts. Sessions can be short, since there is no fail state beyond dying and respawning, but the save lives in the browser, so use the same device and browser if you plan to come back to your world.