thanks for your post
I did not know how to solve the issue with Microsoft thinking that it’s a virus.
you can get higher lvl units by upgrading your castle which will cost 50 coral for the first upgrade.
And the food tile gives +1 food every 4 seconds and coral +1 coral. Upgrading the castle increases the production speed.
the health of your castle drains when an enemy is on a tile adjacent to your castle
I hope this helps