Team Fortress 2 -
"Keep following the pop-ups, as they explain how to make a Sentry. Upgrade it to Level 3, getting metal from your Dispenser or the Ammo crate. After you are done, some Red bots will attack so stand behind your sentry so you'll be safe. Both your Sentry and Dispenser got damaged in the attack, so repair them by hitting them with your wrench (this also costs metal).