regal gust
"When you land on a Celestial Body, the kerbals should send you a little pop-up that that is celebrating your achievement"
#Triumph notification!
finite hamlet
isn't there like a mod on CKAN that has like kerbals achievements?
ruby phoenix
At the very least something reminiscent of the milestone transmissions you'd get in career mode for various things you could do for the first time, like orbiting, landing or planting flags on celestial bodies.