Terraria is a 2D sandbox game with gameplay that revolves around exploration, building, crafting, combat, survival, and mining, playable in both single-player and multiplayer modes.
The game has a 2D sprite tile-based graphical style reminiscent of 16-bit sprites.
Extract the file and run the TerrariaPortable.exe. Click play and allow it to install. Once it finishes, click done. Move the steam_api.dll file to the installation folder (access by clicking the three dots on the bottom right.)
Enjoy