"In the context of Matt 6, where the Lord's Prayer lies embedded, one is strongly inclined to translate the word "kingdom" with "all-importance" - "Your all-importance come." For each of the three surrounding Devotions (charity, prayer, and fasting) teaches that Christians need a sense of God's importance that exceeds their natural sense of other people's importance. (Only when God is more important than people will the Christian be able to overcome the almost irresistible temptation to impress others). [Matthew A Commentary, Frederick Dale Bruner, Revised and Expanded, 2007, Eerdmans].
It does seem like an almost irresistible temptation when it comes to impressing others, making oneself look good in the eyes of others, playing to the crowd, wanting to please. I have known a few blessed souls who seemed unaffected by the opinions of others, who were what they were because they were focused on Jesus Christ and that was pretty much it - it freed them to be unpretentious with others and to love and give to others - such souls humble me and sometimes, sad to say, exasperate me...no doubt because my own selfishness is in stark contrast to their self-forgetfulness.
If I am to pray, "Thy kingdom come," I would do well to keep that prayer and desire on my lips and in my heart and mind throughout the day, to meditate on the all-importance of God; is He more important than my circumstances? Is He more important than the people around me? Who am I serving? To whom am I offering my words and deeds? Do I really want God to make Himself all important in my life?