Initial file download verification code. I'm not sure if it will work, but hopefully. Please watch for bugs, especially when downloading zip files. If it works, I will extend it.

linux-game-manager.sh

@@ -204,6 +204,16 @@ download() {
             echo "Could not download \"$i\"..."
             exit 1
         fi
+        case "${dest##*.}" in
+            "zip")
+                if [[ "$(file -b --mime-type "${cache}/${dest}")" != "application/zip" ]]; then
+                    rm -fv "${cache}/${dest}"
+                    dialog --backtitle "Linux Game Manager" \
+                        --infobox "Error downloading \"${dest}\". Installation cannot continue." -1 -1 --stdout
+                    alert
+                fi
+            ;;
+        esac
     done
 }