Go to GOG.com, search for Terraria, and purchase it (often on sale for $4.99). Once purchased, go to your library and click the "Download Offline Backup Game Installers" button. You will see several files:
Go to GOG.com, search for Terraria, and purchase it (often on sale for $4.99). Once purchased, go to your library and click the "Download Offline Backup Game Installers" button. You will see several files: