36 5 2Actions Report Solution The first fortification I unlocked was the Sentry gun. Simply play a pin of this type 25 times to unlock the achievement.Showing both comments. Leave a comment. When did you unlock this pin?Posted by THEbigBROWNIE on 26 Aug 19 at 19:18 The unlocks are random, but this pin is available from arena 1, so available to potentially unlock straight away.Posted by Mr Gimpson on 26 Aug 19 at 19:27 Leave a comment